Image Gallery: Acquired palmoplantar keratoderma due to hypothyroidism

Funding sources: none. Conflicts of interest: none declared. Dear Editor, A 67‐year‐old woman with a long history of rheumatoid arthritis presented to the dermatology clinic with two years of progressive palmoplantar keratoderma predominantly affecting her soles, with minimal involvement of the palms. Her care had been neglected. Treatment with topical keratolytics and steroids was unsuccessful. Laboratory testing revealed profound hypothyroidism (thyroid‐stimulating hormone 238 μIU mL−1). Malignancy work‐up was unrevealing. Correction of her underlying hypothyroidism with levothyroxine resulted in rapid improvement of her palmoplantar keratoderma with complete resolution in 4 months. The pathogenesis of palmoplantar keratoderma associated with hypothyroidism is poorly understood. Reports suggest dysregulation of the intracellular stratum corneum lipids, although supporting evidence for this connection is poor.1,2