Pruritic Rash in an Elderly Patient with Uncontrolled Diabetes Mellitus

ABSTRACT Objective: Acquired reactive perforating collagenosis is an uncommon skin disease that belongs to a group of dermatologic disorders characterized by transepidermal elimination of dermal material. It is highly associated with systemic disease, primarily diabetes mellitus and dialysis-dependent chronic renal failure. Methods: A 70-year-old female with 20 years of poorly controlled type 2 diabetes mellitus presented with a 6-month history of multiple pruritic erythematous papules and nodules with central hyperkeratosis, involving her right dorsal arm. Histologic examination was consistent with acquired reactive perforating collagenosis. In addition to topical treatment of the disease, the patient was referred to endocrinology for appropriate management of her underlying diabetes mellitus. Results: Ideal treatment should involve both the endocrinologist and dermatologist. Control of the underlying systemic disease, in this case diabetes, as well topical or systemic medications can both help to improve this condition. Our patient re-established care with her endocrinologist who adjusted her medication regimen, resulting in improved hemoglobin A1c values. Our patient additionally benefited from topical betamethasone cream, ammonium lactate, and pimecrolimus application. The combined therapy led to resolution of her pruritic rash. Conclusion: This case highlights the importance of the skin exam by the endocrinologist, as he or she plays a unique role in identifying this rare and difficult-to-treat dermatologic disease. Early detection and prompt referral to a dermatologist are crucial in preventing progression of disease, treating the disease, and improving the patient's quality of life. Abbreviation: ARPC = acquired reactive perforating collagenosis