skip to main content

Perianal Contact Dermatitis — SCE Dermatology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateGenital DermatologyPerianal Contact DermatitisSCE Dermatology

A 55-year-old woman presents with pruritus ani. Examination shows perianal erythema with lichenification. She has haemorrhoids and uses wet wipes containing methylisothiazolinone. Patch testing is positive to MI. What is the most important management step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Eliminate contact with methylisothiazolinone (stop wet wipes, check all products for MI) and use water or bland emollient for cleansing

Pruritus ani with positive patch testing to methylisothiazolinone (MI) from wet wipes represents allergic contact dermatitis — the most important intervention is allergen avoidance. MI-containing wet wipes are a very common cause of perianal contact dermatitis. Management: stop all MI-containing products (check all cleansing products, moisturisers), substitute with water cleansing or bland aqueous cream, use a short course of moderate topical corticosteroid for the acute dermatitis, and provide comprehensive MI avoidance information. The haemorrhoids may contribute but are not the primary issue here. Contact dermatitis from wet wipes is an increasingly common presentation in dermatology and colorectal clinics.

Reference: BAD 2017 Contact Dermatitis; BJD MI Epidemic