Eruptive seborrheic keratosis unveiling underlying primary biliary cholangitis: a case report

Abstract

Eruptive seborrheic keratoses (ESK) is characterized by the sudden onset of multiple benign skin lesions. While typically diagnosed clinically, biopsy may be needed in uncertain cases. Although generally harmless, ESK can serve as a marker for underlying conditions, including malignancy (e.g., gastrointestinal adenocarcinoma), infections, inflammatory disorders, or drug reactions. The Leser-Trélat sign reffering to the abrupt increase in seborrheic keratoses (SK), is particularly associated with malignancy, often adenocarcinoma, and lung cancer. ESK typically involves the back, chest, and extremities. We report a 38-year-old woman presented with abrupt onset of multiple pigmented trunk papules/plaques developing over a 3 months period. Her history included clonazepam use for post-traumatic stress disorder (PTSD). Clinical examination revealed numerous hyperpigmented papules andplaques localized to the trunk, with no other involvement. Macroscopic evaluation identified a 1275 mm brownish tumor. Histopathological analysis showed acanthotic epidermis with basaloid cells and horn pseudocysts, leading to a diagnosis of ESK. Further evaluation revealed primary biliary cholangitis (PBC), despite the absence of symptoms. The patient was started on Ursodeoxycholic acid (UDCA). While the association between PBC and SK is unclear, most studies focusing on conditions like vitiligo and xanthomas. This case suggests that SK may serve as a marker for liver issues. We suggest that further research explore potential links between PBC and ESK, particularly when cutaneous findings precede the hepatic issues diagnosis. © Iranian Journal of Dermatology.