Acquired Palmoplantar Keratoderma Revealing Primary Biliary Cholangitis: Therapeutic Response to Ursodeoxycholic Acid

Acquired palmoplantar keratoderma (PPK) may be associated with drug exposure, inflammatory or infectious dermatoses, malignancies, and systemic disorders. Although several systemic associations have been described, its occurrence in primary biliary cholangitis (PBC) appears to be exceptionally rare. We report the case of a 36-year-old woman with no significant medical history who presented with a three-month history of diffuse, non-pruritic palmoplantar keratoderma refractory to topical therapies. Clinical examination revealed erythema with multiple punctate yellowish hyperkeratotic lesions, some coalescing into plaques, involving the palms and soles. Dermoscopy showed a pinkish background with multiple yellowish, occasionally confluent, plaque-like scales and no visible vascular pattern. Hematologic, renal, thyroid, and infectious investigations were unremarkable. Liver biochemical tests, however, revealed a cholestatic pattern, and anti-mitochondrial antibodies were positive. PBC was diagnosed based on the combination of cholestatic liver biochemistry and anti-mitochondrial antibody positivity. Treatment with oral ursodeoxycholic acid was followed by progressive improvement of the palmoplantar lesions, with marked clearing and normalization of liver biochemical tests after three months. This observation adds to the very limited literature linking acquired PPK with PBC and highlights the importance of investigating an underlying systemic disorder in otherwise unexplained or treatment-refractory acquired keratoderma.