What is this odd rash in this mansí underarms?
28 year old man presents for the evaluation of a rust-brown colored, papular, pruritic rash in his axillae of 4 months duration. Aside from being obese, he was otherwise healthy and had not changed his antiperspirant routine of several years, but had started working out on a regular basis with several showers per day.
What is your diagnosis?
(Intertriginous) Granular Parakeratosis
This is a very odd condition that occurs most commonly in the axillary folds of women, but can be seen in any intertriginous area, in both sexes. Clinically it presents as coalescing brown papules that may also be pruritic. Histologically, there is a thickened stratum corneum with adherent compact parakeratosis and retention of keratohyalin granules. Ectasia is also present. The etiology is unclear, some postulating a defect in fillagrin production. According to Andrew’s, it probably represents an irritant response to rubbing or to antiperspirants.
In this particular case, (confirmed by biopsy) because the areas were pruritic, I gave him hydrocortisone valerate 0.02% cream, BID x 2-3 weeks. The lesions had resolved when I saw him back at a 6 week follow up.
Charles E. Crutchfield III, MD
Clinical Adjunct Associate Professor of Dermatology
University of Minnesota Medical School
Medical Director, Crutchfield Dermatology
For additional information please see the eMedicine article, linked below: