Anal itching

Thank you for the concise summary article on anal itching, published in the BMJ 5th November 2016 edition. Peri-anal dermatoses and pruritus-ani are common and socially embarrassing conditions that are often poorly managed. There is a lack of published data on the role of patch testing in patients with these conditions.

We would like to draw attention to the authors and your readers about the importance of patch testing in this group of patients. Our study, the largest reported case series, in the Cutaneous Allergy Clinic, at St John’s Institute of Dermatology, recently published in Contact Dermatitis, 2016, 74, 295-319, strongly recommends patch testing in all patients with peri-anal dermatoses or pruritus ani, as approximately 20% of them will have relevant allergens to be avoided.

Testing with the European baseline series, other relevant series and the patient’s own products should be undertaken. In our case series, methylchloroisothiazoline/ methylisothiazoline (MCI/MI) was the most common allergen implicated in pruritus ani, frequently from the use of wet wipes and other toiletries.

Apart from wet wipes, clinicians should ask about other suspected triggers for peri-anal disease, such as sanitary towels, medicaments (including haemorrhoid medications and suppositories), toiletry sprays/deodorants, and clothing.

Kind regards,

Dr. Mohammed J. Abu-Asi and Dr. Jonathan M. L. White
Cutaneous Allergy Clinic, St John’s Institute of Dermatology,
Guy’s & St Thomas’ Hospitals NHS Foundation Trust,
London, SE1 9RT, UK
E-mail: mohammed.abu-asi@doctors.org.uk

Competing interests: No competing interests