Establishing diagnostic strategies for cannabis allergy

ABSTRACT

Introduction

Cannabis is the most widely consumed illicit drug in the world and carries a risk of severe IgE-mediated allergic reactions, requiring appropriate diagnostic management. Currently available diagnostics are still relatively limited and require careful interpretation of results to avoid harmful over- and underdiagnosis.

Areas covered

This review focuses on the most up-to-date understandings of cannabis allergy diagnosis, starting with the main clinical features of the disease and the allergenic characteristics of Cannabis sativa, and then providing insights into in vivo, in vitro, and ex vivo diagnostic tests.

Expert opinion

At present, the diagnosis of IgE-mediated cannabis allergy is based on a three-step approach that starts with accurate history taking and ends with a confirmation of sensitization to the whole extract and, finally, molecular components. Although much has been discovered since its first description in 1971, the diagnosis of cannabis allergy still has many unmet needs. The lack of commercial standardized and validated extracts and in vitro assays makes a harmonized workup of cannabis allergy difficult. Furthermore, the epidemiological characteristics, and clinical implications of sensitization to different molecular components are not yet fully known. Future research will complete the picture and likely result in an individualized and standardized approach.

KEYWORDS:

• BAT
• cannabis allergy
• lipid transfer proteins
• OEEP2
• pMAT

Article highlights

• Cannabis is the most widely consumed illicit drug in the world, and its consumption is expected to grow further with likely repercussions on the prevalence of cannabis allergy;

• Cannabis can give allergic reactions in all its forms and modes of intake;

• Respiratory and cutaneous symptoms are the most common complaints, and up to 20% of allergic reactions to cannabis can be severe;

• Can s 3, a non-specific lipid transfer protein (nsLTP), is the major cannabis allergen in north-western Europe, and its sensitization can cause a cannabis-related food allergy syndrome;

• Hemp-specific IgE or a positive skin prick test with cannabis crude products or extracts may be clinically irrelevant; component resolved diagnosis (CRD) may help confirming clinical relevance;

• Further studies on CRD will provide a personalized approach in the future.

Acknowledgments

The Antwerp University Hospital and AZ Jan Palfijn Hospital Ghent are excellence centers of the World Allergy Organization (WAO).

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

D Ebo is a senior clinical researcher of the Research Foundation Flanders/Fonds Wetenschappelijk Onderzoek (FWO: 1800614N). V Sabato is a senior clinical researcher of the Research Foundation Flanders/Fonds Wetenschappelijk Onderzoek (FWO: 1804518N). This work was supported by the Agency for Innovation by Science and Technology (IWT-TBM 140185).