Erythroderma as the first paraneoplastic manifestation of early-stage lung squamous cell carcinoma: a rare case report

Abstract

Erythroderma is a severe inflammatory dermatosis affecting over 90% of the body surface area and commonly arises from pre-existing dermatoses or drug reactions. Paraneoplastic erythroderma is rare but clinically significant, especially in elderly patients, as it may precede the diagnosis of internal malignancy. Early identification and evaluation are essential for timely detection. An 85-year-old male with a 40 pack-year smoking history presented with rapidly progressive generalized erythema and scaling, without prior dermatologic disease or new medication exposure. Skin biopsy revealed subacute spongiotic dermatitis with dermal eosinophils. Given the unexplained presentation and patient’s risk factors, systemic evaluation was pursued. Imaging demonstrated a right lower-lobe perihilar mass, and bronchoscopy with biopsy confirmed moderately differentiated squamous cell carcinoma of the lung. Supportive dermatologic therapy was initiated and sequential chemo-radiation was planned. Improvement in the erythroderma paralleled initiation of cancer-directed therapy. Erythroderma can rarely be the first manifestation of lung squamous cell carcinoma. In elderly patients with unexplained erythroderma, especially those with smoking history, malignancy screening should be undertaken after exclusion of common causes.