Tinea incognito is a dermatophyte infection of the skin that presents atypically because it has previously been treated with imunnosuppresive medication. Herein we present a case of a middle-aged man who was initially clinically diagnosed to have plaque-type psoriasis on his arms. Over the course of two months of topical hydrocortisone and calciptriol treatment as well as phototherapy, the rash worsened. At the time of presentation to hospital the patient had a pruritic, widespread, sloughing, erythematous rash with areas of eschar. A punch biopsy skin confirmed dermatophyte fungal infection of the skin. Fungal culture was positive for Trichophyton Rubrum and the eruption resolved with systemic anti-fungal therapy. Patient specific risk factors for atypical presentation included poor hygiene and hepatatic disease.

Objective: Combination topical clotrimazole/ betamethasone dipropionate (C-BM) contains a high-potency topical corticosteroid and is not infrequently prescribed for inappropriate patient groups and body sites. Use of C-BM can lead to inadequate clearance or exacerbation of fungal infections as well as cutaneous atrophy, striae, and other skin maladies. Methods: We performed a retrospective chart review of 1,978 clinical visits where C-BM was prescribed within the University of Utah Health system between 2014 and 2018 to better understand current prescribing patterns. Results: 1,974 prescriptions were written for C-BM. 91.6% of patients were at least the recommended age of 17 years. C-BM was most commonly prescribed for rashes of an inflammatory (42.2%) or fungal nature (38.1%). Clotrimazole/betamethasone dipropionate was prescribed for sensitive areas (face, axillae, groin or diaper region) in 48.9% of patients. Family medicine clinicians prescribed 58.3% of C-BM prescriptions, whereas dermatology clinicians accounted for 3.4%. Conclusion: We strongly recommend clinicians use alternative treatments for rashes or refer to dermatologists.