Pruritus intensity assessment: challenge for clinicians

Abstract

Pruritus is defined as an unpleasant sensation that provokes a desire to scratch. This definition underlines a subjective character of itching and therefore any objective measurement of its intensity constitutes a significant clinical difficulty. Various instruments and methods have been used over time to provide a more reliable and accurate evaluation of pruritus, however, none of them have become a gold standard, unanimously accepted by all experts. The authors have reviewed current literature data on the assessment of pruritus indicating existing shortcomings and underlying the need for future studies.

Keywords::

• itch
• measurement
• validity
• VAS

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All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 70% minimum passing score and complete the evaluation at www.medscape.org/journal/expertdermatol; (4) view/print certificate.

Release date: 31 May 2013; Expiration date: 31 May 2014

Learning objectives

Upon completion of this activity, participants will be able to:

• • Analyze challenges in the measurement of pruritus

• • Compare unidimensional scales in the measurement of pruritus

• • Distinguish elements of the “5-D” questionnaire to measure pruritus

• • Evaluate means to measure psychosocial outcomes among patients with pruritus

Financial & competing interests disclosure

EDITOR

Elisa Manzotti

Publisher, Publisher, Future Science Group, London, UK.

Disclosure: Elisa Manzotti has disclosed no relevant financial relationships.

CME AUTHOR

Charles P Vega, MD

Associate Professor and Residency Director, Department of Family Medicine, University of California, Irvine, CA, USA.

Disclosure: Charles P Vega, MD, has disclosed no relevant financial relationships.

AUTHORS AND CREDENTIALS

Adam Reich

Venereology and Allergology, Wroclaw Medical University, Wroclaw, Poland.

Disclosure: Adam Reich has disclosed no relevant financial relationships.

Jacek C Szepietowski

Department of Dermatology, Venereology and Allergology, Wroclaw Medical University, Wroclaw, Poland.

Disclosure: Jacek C Szepietowski has disclosed no relevant financial relationships.

Pruritus is defined as an unpleasant sensation that provokes a desire to scratch [1]. This old definition underlines a subjective character of itching, as it is a sensation perceived by an individual and thus an objective measurement of its intensity constitutes a significant clinical difficulty. Although a short-term condition, acute pruritus may be considered a defensive mechanism that alarms a human being or an animal who, for example, think they are being bitten by some parasite, a chronic, long-lasting itching represents a significant medical problem. It is often responsible for marked morbidity, quality of life impairment and, in some patient populations, even increased mortality [2,3]. Pruritus was shown to be present in up to 20% of the general population [4–6]. This symptom may accompany a long list of skin as well as systemic, neurological or psychiatric diseases. Of note, it is considered to be the most common ailment of dermatological conditions. However, despite its high prevalence and significant importance, a valid assessment of itching remains elusive due to its subjectivity. Various instruments and methods have been used over time to provide a more reliable and accurate evaluation of pruritus. Here, the authors have reviewed current literature data on the assessment of pruritus, indicating the need for future studies.

Multidimensional characteristics of pruritus

Pruritus is a common symptom of various diseases. However, it is still not clear whether it represents a single sensation type or is rather a common descriptive term for various, closely related feelings, as patients describe sensations such as tickling, tingling, stinging, burning and many others. Thus, it is difficult to say whether pruritus in one disorder is of the same quality or not in comparison to itching in another disorder.

Furthermore, itching can be assessed according to various dimensions; for example, according to duration (acute vs chronic pruritus), localization (localized vs generalized pruritus), and so on (Table 1). Since one of the most important features of pruritus is its intensity, a long list of attempts have been made over past decades to provide the most valid measurement of itching severity. A reliable measurement of pruritus intensity is of great importance, especially for clinical studies assessing the efficacy of various antipruritic medicines [7].

Pruritus intensity can be measured using the Verbal Rating Scale (VRS), Visual Analog Scale (VAS), various questionnaires or limb movement measurements. Moreover, assessing quality of life, depression, anxiety and other mental parameters may further support a beneficial effect of studied antipruritic therapies, as these parameters usually improve in conjunction with pruritus intensity lowering. However, to date, no single method has been recognized as a gold standard and it is widely accepted that at least two different methods are usually needed to assess itch intensity reliably in clinical studies.

Methods of pruritus measurements

As mentioned above, variable methods exist to assess itch. They can be divided into several groups: unidimensional scales for itch severity measurement (e.g., VRS, VAS, numerical rating scale [NRS]), questionnaires (e.g., 5D scale, four-item questionnaire), measurement of scratching episodes (e.g., measurement of limb movements), imaging of brain activity, measurement of itch threshold, and scales assessing the psychosocial condition of the patient related to itch by evaluation of the level of quality of life impairment, depression, anxiety, stigmatization and others (e.g., ItchQoL, Dermatology Life Quality Index [DLQI] and Beck’s Depression Inventory).

Unidimensional scales for itch severity measurement

Unidimensional scales such as VRS, VAS and NRS are probably the most widely used methods of itch measurement due to their simplicity and rapidity. Originally, they were developed to assess pain and were then adopted for pruritus. A number of pain studies demonstrated their value in daily routine practice [8–14]. However, until recently these scales had not been validated in itch patients. Therefore, the International Forum for the Study of Itch (IFSI) [101] formatted a special interest group on scoring itch, which has initiated studies on the use of the abovementioned instruments in the assessment of pruritus.

VRS enables the patient to verbally express the degree of pruritus they feel. This is probably the easiest method of pruritus assessment; however, to date there is no consensus on how many degrees should be included in this scale. Phan et al. [15] used a four-point scale (none, mild, moderate and severe pruritus), while our group proposed a five-point scale (none, mild, moderate, severe and very severe pruritus) [16]. Moreover, ‘minimal pruritus’ can be added between ‘none’ and ‘mild pruritus’ and, if necessary, ‘extremely severe pruritus’ is also possible. Such variability in VRS constitutes a major limitation of this scale, as different studies may use different versions of VRS, making comparison of their results very difficult. Furthermore, a very limited number of options to describe pruritus might result in greater variability of pruritus intensities within one group. Thus, sensitivity of VRS to changing pruritus severity during antipruritic therapy seems to be quite limited. However, VRS can still be the most suitable pruritus assessment method for certain populations; for example, for elderly people or for individuals with cognitive problems.

VAS is a 10-cm long line that patients mark by crossing the line that corresponds to the severity of experienced itching. Furue et al. has recently performed a short survey among pruritus experts to unify the descriptions of VAS extremes [17]. Based on this consensus, VAS should start with ‘no itch’ (0) and finish with ‘worst imaginable itch’ (10) [17]. VAS is usually demonstrated as a horizontal line; however, the line can also be oriented vertically. Despite the fact that very few and insignificant differences between the horizontal and vertical VAS were observed during itch [16], as well as pain assessment [8,13], the authors would like to suggest the use of horizontal VAS to avoid any theoretically possible bias in the future while comparing studies using VAS with different orientations. As mentioned above, IFSI initiated a process of validation of unidimensional methods of itch assessment. Based on recently published studies [15,16], it could be stated that VAS is a valid, reliable and repetitive method of itch measurement. VAS showed a very good correlation with NRS and VRS [15,16] as well as with the itch questionnaire scoring [18], indicating a good convergent validity of VAS in the pruritus assessment. Significant differences in VAS scoring between various itch categories of VRS confirmed a content validity of VAS. VAS also showed good test–retest reproducibility (intraclass correlation coefficient: 0.88). Based on assessing pruritus in two different populations (Polish and Japanese), our group has also proposed a categorization of VAS for a better suitability of this method in routine clinical practice. Scoring was categorized into none (0 points), mild (0.1–3.9 points), moderate (4.0–6.9 points), severe (7.0–8.9 points) and very severe (9.0–10.0 points) pruritus [16].

Although VAS seems to be a valuable method of pruritus measurement, some limitations of this instrument should be mentioned. To date, it is still not unanimously accepted which time period in respect to itching should be assessed with VAS. It appears that for single assessment the patient should be asked about intensity (average or maximal) within the previous 24 h to 3 days. It has also not been determined how often pruritus should be evaluated in clinical trials. However, according to our observation, it could be suggested that twice-daily VAS or NRS assessment provides the most reliable data [19]. Furthermore, more studies on the determination of minimal clinically important differences in VAS scoring should be performed in the near future in order to be able to better assess treatment success with antipruritic therapies. According to our preliminary results it seems that improvement in at least three points is of clinical relevance [19]. On the other hand, deterioration of only two points of VAS scoring means a significant increase in pruritus intensity [19]. It must also be underlined that VAS is not suitable for people with motor or cognitive problems that preclude understanding the scale or marking the line with a pen – an issue especially important for elderly people and for young children [8,9]. Prior to itch evaluation with VAS, each patient should be precisely instructed on how to use this scale in order to minimize the risk of unnecessary confusion or mistakes. Finally, VAS only gives information about itch intensity; thus, multidimensional assessment tools would be more suitable if more detailed pruritus evaluation is needed to provide more comprehensive information about various aspects of itching.

NRS is a very similar method of pruritus assessment to VAS. It provides numerical values of pruritus severity from 0 (no pruritus) to 10 (the most severe pruritus the patient can imagine), and each patient must indicate a number that corresponds to the perceived itch intensity. Based on our own data, it seems that fewer patients had problems with NRS compared with VAS, and more patients indicated NRS as a better scale for pruritus assessment than VAS, although the preferences are very individual [19]. The results achieved with NRS are similar to and highly correlated with results obtained with VAS; however, it was observed that the mean NRS scoring of pruritus was slightly, albeit significantly, higher than with VAS. Similar observations were noted during pain assessment [14,20,21]. It is still unclear whether this difference is of clinical relevance, but in our opinion both scales cannot be used interchangeably, and if assessment was started with one scale then it must be uniformly used for the duration of patient observation. Moreover, NRS should not be considered a verbal version of VAS and the results obtained with NRS cannot be directly compared with VAS scoring.

Itch questionnaires

Questionnaires constitute another method of pruritus assessment. A number of instruments have been developed to date [18,22–27]. The major advantage of questionnaires is the possibility of assessing different characteristics of pruritus, including both physical as well as mental aspects of itching. Darsow et al. developed an ‘Eppendorf Itch Questionnaire’ to assess pruritus in atopic dermatitis patients [22]. This questionnaire was based on the McGill pain questionnaire and included 80 itch descriptors [22]. Using this questionnaire, a very detailed and exact pruritus characteristic is possible, and thus it is well-suited for scientific purposes with the aim of itch analysis. However, such instruments are usually considered too lengthy and not suited for repeated assessments, especially in clinical settings. Moreover, they usually require some psychometric expertise and time for proper interpretation, which limits their more frequent use. In 2010, Elman et al. proposed a new, simple instrument for itch assessment based on five dimensions: duration of itch, degree (severity), direction (worsening or improvement), disability (itch influence on various activities) and distribution (localization of itch) [25]. The final 5D scoring ranges from 5 (no pruritus) to 25 (most severe pruritus). The 5D scale showed good convergent validity, internal consistency, reliability and sensitivity to change in pruritus intensity [25]. Here, the authors would like to present another simple four-item questionnaire, which was successfully applied by our group in a number of studies on different itch types [18,28–30]. This questionnaire has recently been shown to be a valid method of pruritus measurement [31]. Despite the fact that it mainly concentrates on physical features of pruritus and does not assess mental domains, the questionnaire only contains four questions, resulting in a very short time of completion and making it suitable for routine clinical use (Table 2). Moreover, a significant correlation was observed between the four-item questionnaire and other mental parameters, such as quality of life impairment, depression level and stress severity [29,30]. Therefore, the authors do believe that it can be helpful for other clinicians.

Despite a number of itch questionnaires existing, none have been more widely accepted. Therefore, the IFSI has made an effort to develop a new questionnaire that will overcome the shortcomings of previous questionnaires and will be more frequently used in clinical trials and in daily practice. Recently they have published a statement paper on the properties that should be fulfilled by a newly developed instrument [32]. According to the published recommendation, an ‘ideal’ questionnaire should consider the patients’ perspective, the medical doctors’ perspective and the need for various measurements in clinical trials [32]. It should be easy to understand and to complete (patients’ perspective), should provide important information about relevant characteristics of itch for medical doctors and discriminate between the different types of pruritus (physician perspective), be useful as an outcome measure in clinical trials, and should be able to detect changes in itch over time (clinical trial perspective) [32]. The questionnaire should contain questions about localization, duration, frequency and intensity of itch, sensory qualities, scratch response, opinion of origin, affective dimensions, aggravating or relieving factors, disability, response to current and previous treatments, itch cognition, coping and quality of life. Meeting all these requirements is a significant challenge, and therefore the IFSI special interest group proposed to develop a double questionnaire with a short and long version.

Measurements of scratching episodes

Itching provokes a desire to scratch. Therefore, the measurement of scratching might provide valuable data about itch intensity. Measurement of scratching might simply be based on counting the number of skin lesions induced by scratching, such as excoriations or areas with lichenification. However, it must be remembered that not all patients scratch their skin with nails; sometimes they only rub the itchy areas, thus there is not a simple relationship between itch intensity and the degree of scratch lesions. Furthermore, in some itchy skin diseases, like in urticaria, excoriations or other scratch marks are observed on very rare occasions.

Other, more sophisticated, methods have thus been used to assess the degree of scratching, such as nocturnal wrist measurements, fingernail vibration transducers (pruritometer), acoustic evaluation systems of scratching or infrared camera videotaping. However, this methodology is expensive, time consuming and results are difficult to interpret, as many movement episodes are not necessarily connected with itching [33]. Interestingly, a recent study by Murray and Rees has showed that there is a poor correlation between VAS and actigraphic measures of scratch, a phenomenon that requires further study and explanation [33]. In addition, most of the available devices only enable the evaluation of nocturnal pruritus, and therefore are not well suited for the assessment of itch, which is present during the day. As a consequence, wrist movement measurement is not widely used, even in scientific studies, but nevertheless these methods need more attention as they may become a routine diagnostic tool in the near future.

Assessment of brain activity

Assessment of brain activity (functional imaging techniques, like functional magnetic resonance or positron emission tomography) during itch episodes is another possible option to objectively document pruritus. Several studies have revealed that brain processing of itchy stimuli in patients with chronic pruritus differs from that observed in healthy controls [34–36]. Thus, it could be suggested that mapping of brain activity during itch episodes may provide valuable information helping in the assessment of the degree of itch intensity. However, current data are rather preliminary, as there is great variability in currently achieved results with different diagnostic techniques. These methods are also too expensive to be used as a routine diagnostic procedure, and thus they are used only for scientific purposes to better understand what happens within the brain upon itchy stimuli [34–36].

Measurement of itch threshold

As mentioned above, patients with chronic pruritus showed different brain processing of itch stimuli compared with healthy controls. However, it was also suggested that subjects with chronic pruritus might also be more sensitive to itchy stimuli due to lowering of itch threshold at the periphery [37–40]. For instance, it was observed that tactile threshold in patients with nodular prurigo was lower than in controls and this abnormality was reversed by capsaicin, suggesting the involvement of neuropeptides, mainly substance P [37]. In addition, the basal skin blood flow level fluctuated more in itchy skin areas than in the healthy skin areas of nodular prurigo patients, suggesting an abnormal spontaneous activity of nociceptive peripheral nerve fibers and a consequent release of vasoactive agents from their terminals (axon reflex) [37]. It was also demonstrated that electric stimulation might evoke pruritus in patients with chronic itch, making the threshold assessment relatively easy in clinical settings [41–43]. Kobayashi et al. observed that patients with atopic dermatitis, a chronic inflammatory skin disease accompanied by severe itching, showed a lower barrier function and lower current perception threshold (CPT) than normal individuals, and the CPT was found to be inversely correlated with transepidermal water loss levels, a measurement of epidermal barrier disruption [38]. However, not all studies were able to demonstrate CPT lowering in patients with atopic dermatitis. Ikoma et al. did not find any difference between healthy subjects and patients with atopic dermatitis in their response to electrical (0.08–8 ms; 2–200 Hz) and chemical (histamine iontophoresis; 100 microC) stimulation [41]. Accordingly, Mori et al. observed no statistically significant difference in CPT among extrinsic atopic dermatitis, intrinsic atopic dermatitis and normal controls [42]. In contrast, our group found an even higher sensory threshold to electric current stimulation in patients with atopic dermatitis or psoriasis than in healthy volunteers, although no significant differences were found between subjects with atopic dermatitis and psoriasis [43]. Our results are in accordance with the observations made by Yudina et al., who documented elevated thermal thresholds in patients with atopic dermatitis [40].

Nevertheless, it appears that patients with chronic itch may demonstrate small nerve fiber dysfunction, and measurement of pruritus threshold might be a valuable and promising adjunct to other methods of itch assessment. This suggestion may be supported by the observation that CPT was significantly correlated with skin surface hydration and inversely with transepidermal water loss in intrinsic atopic dermatitis, as well as with the VAS scoring of itch in extrinsic atopic dermatitis [42]. Our group also observed a significant correlation between CPT and pruritus severity. The most significant relationships were found for electric current frequency of 5 Hz, indicating that the most relevant population of nerve fibers conducting pruritic stimuli are unmyelinated C-fibers that are selectively activated by a 5-Hz alternating current [43].

Scales assessing the psychosocial condition

Itch may greatly impact the patients’ psychosocial condition [29,30,44]. Therefore, assessment of mental parameters may provide valuable supportive information about the severity of pruritus. A number of scales have been developed, both generic (e.g., General Health Questionnaire, SF-12, SF36, EQ-5D) as well as skin specific (e.g., Skindex-29, DLQI), which can be used to evaluate the quality of life of patients with various conditions, including chronic itch. Among the skin disease-specific instruments, our group most commonly used DLQI to assess patients’ quality of life [29,30,44], because this questionnaire is available in many languages, has a child-adapted version, has defined cutoffs for the degree of quality of life impairment and ensures rapid completion by the patient (less than 3 min) [45]. However, it must be mentioned that DLQI mainly concentrates on patient functioning, while mental impairments are assessed to a lesser degree by this scale [45]. Importantly, a new itch-specific quality of life questionnaire (ItchyQoL) has recently been developed by Desai et al. [46]. This is the first questionnaire solely dedicated to assessment of the influence of itch on quality of life by evaluating three dimensions, namely, symptoms, emotions and functioning [46]. However, to date, this questionnaire is only available in English, which limits its wider use.

Chronic itch frequently causes significant mood impairment. Therefore, measurement of depressive and/or anxiety symptoms may further support valid assessment of pruritus. A number of self-administered questionnaires are available and have been previously used in itch patients (e.g., Hospital Anxiety and Depression Scale, Beck’s Depression Inventory and Hamilton Rating Scale for Depression). However, it must be underlined that definite diagnosis of depression and/or anxiety disorder may only be made based on psychiatric examination, while the abovementioned instruments are suitable for screening of psychiatric symptoms. They only enable evaluation of the severity of depressive and anxiety symptoms. If based on them a depression or anxiety disorder is suspected, then a psychiatric consultation is mandatory.

Expert commentary

Valid assessment of pruritus still remains a big challenge – both for researchers as well as for clinicians. Unidimensional scales, such as VAS or NRS, seem to be a valuable method of pruritus measurement due to their simplicity and rapidity. However, as they only assess itch intensity and omit other important aspects of pruritus sensation, they should not be used without the support of other instruments. A number of other methods have been developed and tested in pruritus assessment, but none of these have been accepted by all experts as a gold standard. Therefore, further studies are needed on this issue to enable the evaluation of pruritus in a more accurate and valid way.

Five-year view

The IFSI, a scientific society dedicated to research on itch, has made great efforts since its origin in 2005 to improve our knowledge about the pathogenesis and proper management of pruritus. One of its major achievements was the unification of itch classification. Currently, most ongoing studies supervised by the IFSI are concentrated on methods of pruritus assessment. Despite many issues that have already been answered, there are still a number of problems that need to be solved in the near future. We believe that, within the next 5 years, a new, widely accepted itch questionnaire will be developed to provide a valid instrument for multiple studies. Thus, better comparisons of various pruritus subtypes and different treatment strategies will be possible. Furthermore, currently used unidimensional scales such as VAS and NRS will be better characterized, especially regarding the frequency of their use and the minimal clinically important difference. In addition, new, so-called dynamic scales will also be available soon. We also expect more frequent use of ItchQoL, an itch-specific quality of life instrument, in various ethnic groups with different pruritus subtypes, as national language versions are currently under development in many countries. Finally, we believe, that studies on itch threshold will enable a more accurate and objective measurement of pruritus and will result in construction of a device that can be used in clinical settings.

Table 1. Various dimensions of pruritus assessment.

Assessment of pruritus	Type of pruritus	Definition
According to symptom duration	Acute pruritus	Duration of symptoms <6 weeks
	Chronic pruritus	Duration of symptoms >6 weeks
According to distribution	Localized pruritus	Pruritus limited to a defined body area
	Generalized pruritus	Pruritus present on the entire body surface
According to the skin lesion characteristics	Pruritus on primarily diseased, inflamed skin	Presence of primary skin lesions accompanied by pruritus
	Pruritus on nondiseased, noninflamed skin	Pruritus on clinically normal skin
	Pruritus with chronic secondary scratch lesions	Presence of secondary scratch lesions
According to etiology	Dermatologic pruritus	Pruritus arising from diseases of the skin
	Systemic pruritus	Pruritus arising from diseases of organs other than the skin
	Neurological pruritus	Pruritus arising from diseases or disorders of the central or peripheral nervous system
	Psychogenic pruritus	Somatoform pruritus with comorbidity of psychiatric and psychosomatic diseases
	Mixed pruritus	Overlapping and coexistence of several diseases
	Other pruritus	Pruritus of undetermined origin
According to intensity	Mild pruritus	Based on patient verbal assessment or VAS/NRS scoring (0.1–3.9 points)
	Moderate pruritus	Based on patient verbal assessment or VAS/NRS scoring (4.0–6.9 points)
	Severe pruritus	Based on patient verbal assessment or VAS/NRS scoring (7.0–8.9 points)
	Very severe pruritus	Based on patient verbal assessment or VAS/NRS scoring (9.0–10 points)

NRS: Numerical rating scale; VAS: Visual analog scale.

Table 2. Four-item itch questionnaire.

No.	Pruritus feature	Categories	Scoring	Maximal scoring
1	Distribution	Pruritus at a single location	1	3
		Pruritus at multiple locations	2
		Generalized pruritus	3
2	Severity	Pruritus without the need to scratch	1	5
		Pruritus with the need to scratch but without excoriation	2
		Pruritus unrelieved by scratching but without excoriation	3
		Pruritus accompanied by excoriation	4
		Totally restless	5
3	Frequency	Four short episodes (<10 min)	1	5
		One long episode (>10 min)	1
		Continuous pruritus	5
4	Sleep disturbances	Each episode of awakening due to pruritus	2	6

Reproduced with permission from [31], © 2012 Termedia.

Key issues

• • Pruritus is defined as an unpleasant sensation that provokes a desire to scratch.

• • An objective measurement of itch intensity constitutes a significant clinical difficulty due to its subjective character.

• • Itching can be assessed according to various dimensions; for example, duration (acute vs chronic pruritus), localization (localized vs generalized pruritus) and many others.

• • To date, no single method of pruritus measurement has been recognized as a gold standard, and it is widely accepted that at least two different methods are usually needed to reliably assess itch intensity in clinical studies.

• • Methods for itch assessment can be divided into several groups: unidimensional scales for itch severity measurement, questionnaires, measurement of scratching episodes, imaging of brain activity, measurement of itch threshold, and scales assessing the psychosocial condition of the patient related to itch.

• • The Verbal Rating Scale enables the patient to verbally express the degree of pruritus they feel.

• • The Visual Analogue Scale is a 10-cm-long line starting with ‘no itch’ and finishing with ‘worst imaginable itch’, on which patients mark by crossing the line according to the severity of experienced itching.

• • The Numerical Rating Scale provides numerical values of pruritus severity from 0 (no pruritus) to 10 (the most severe pruritus the patient can imagine), and each patient must indicate a number that corresponds to perceived itch intensity.

• • Itch questionnaires provide the possibility of assessment of different characteristics of pruritus, including both physical as well as mental aspects of itching; however, they are usually considered to be too lengthy and are not suited for repeated assessments, especially in clinical settings.

• • As itching provokes a desire to scratch, the measurement of scratching might provide valuable data about itch intensity.

• • Assessment of brain activity, because of high costs and inconclusive currently available data, is used only for scientific purposes.

• • Measurement of pruritus threshold might be a valuable and promising adjunct to other methods of chronic itch assessment in the future.

• • As itch may greatly impact the patient’s psychosocial condition, assessment of mental parameters may provide valuable supportive information about the severity of pruritus.

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Website

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Pruritus intensity assessment: challenge for clinicians

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Activity Evaluation: Where 1 is strongly disagree and 5 is strongly agree

	1	2	3	4	5
1. The activity supported the learning objectives.
2. The material was organized clearly for learning to occur.
3. The content learned from this activity will impact my practice.
4. The activity was presented objectively and free of commercial bias.

1. You are seeing a 25-year-old man with a history of chronic urticaria. He complains of ongoing pruritus. What should you consider in general regarding the symptom of pruritus and its measurement?

• □ A The prevalence of pruritus is approximately 1% in the general population

• □ B Pruritus generally does not represent a single type of sensation

• □ C A Visual Analog Scale (VAS) has been accepted as the gold standard in the assessment of pruritus

• □ D At least 4 methods of measuring pruritus per day are necessary to produce reliable results in clinical studies

2. You decide to employ a unidimensional scale in order to assess this patient’s pruritus over time. Which of the following statements regarding these instruments is most accurate?

• □ A They are probably the most widely used means to measure pruritus

• □ B The best feature of the verbal rating scale is its uniformity across different instruments

• □ C VAS does not correlate well with other unidimensional scales

• □ D VAS should account for itch symptoms over the past 2 weeks

3. You also want the patient to complete a ‘5-D’ itch questionnaire. Which of the following is one of the ‘D’ domains of this questionnaire?

• □ A ‘Distance’ across the pruritic area

• □ B ‘Distribution’ of itch

• □ C ‘Degeneration’ of skin in the pruritic area

• □ D ‘Drop’ in pruritus symptoms with particular treatments

4. The patient has a flat affect, and you wonder whether his long history of pruritus has affected his mood. Which of the following statements regarding scales assessing the psychosocial condition of this patient is most accurate?

• □ A There are no skin-specific measurements of quality of life

• □ B The Dermatology Life Quality Index (DLQI) requires approximately 30 minutes to complete

• □ C ItchyQoL is limited to the assessment of pruritus on function alone

• □ D The DLQI is available in many languages