Screening for hydroxychloroquine toxicity in children

The screening paradigm for hydroxychloroquine retinal toxicity has garnered significant attention of late. Marmor recently presented an insightful commentary on the relative utility of screening modalities for hydroxychloroquine toxicity1. Additionally, the American Academy of Ophthalmology (AAO) has updated guidance for the screening of retinal toxicity; however, the most current guidelines from the AAO and Royal College of Ophthalmologists do not provided specific guidelines for pediatric patients2,3. This does not represent an oversight by the authors, but rather is the result of a lack of primary literature3. In the absence of such evidence, the Royal College of Ophthalmologists advocates for locally agreed upon protocols3.

Hydroxychloroquine is used in pediatric rheumatologic and dermatologic diseases; however, investigations into its retinal toxicity in children is sparse and mostly limited to investigations of children exposed in utero where the risk of retinal toxicity appears to be limited4. Fundamental differences in pharmacokinetics as well as in retinal physiology and anatomy likely result in differences in the toxic threshold in children compared to adults. Tools for screening may be limited by patient age and cooperation and, to a lesser extent, by the lack of normative data or well defined criteria for pathologic change. This concern is heightened in younger children whereas adolescents would be anticipated to be more similar to their adult counterparts. There is a need for greater investigation to create a comprehensive evidence based paradigm for the management of children on hydroxychloroquine therapy. Until then, screening of young patients remains at the discretion of individual ophthalmologists and/or referring rheumatologist/pediatricians and will be based on speculation and conjecture.