Hyperkeratosis Lenticularis Perstans (Flegel's Disease) in a Middle-Aged Man: A Rare Keratinization Disorder

Flegel disease, also known as hyperkeratosis lenticularis perstans, is a rare cutaneous disease. Here, we report a case of a 56-year-old man who presented with a history of asymptomatic skin lesions that had gradually increased in number over the past year, in the absence of any significant medical history or known predisposing factors for Flegel disease. Skin examination revealed multiple punctate, scaly, blanchable, erythematous papules measuring 1-2 mm in diameter and distributed symmetrically on both lower extremities. Scales were adherent to the peripheral edges of the papules. Palms, soles, scalp, and mucous membranes were not involved, and there was no family history of similar lesions. Punch biopsy revealed epidermal atrophy with an overlying zone of ortho-hyperkeratosis, contrasting with the normal keratin layer. The papillary dermis showed a lichenoid infiltrate and dilated blood vessels. These clinico-pathological findings correlated well with the clinical appearance of multiple scaly erythematous papules and confirmed the diagnosis of Flegel disease. Topical therapy with 0.1% betamethasone valerate ointment was started twice daily. The patient showed mild improvement with reduced scaling and erythema, and no adverse effects were observed. Regular periodic follow-up was scheduled, but the patient was lost to follow-up.