Dermatosis neglecta (DN) is a rare condition, often linked to psychosomatic disorders, with an unclear etiology. Chilblain lupus erythematosus (CHLE) constitutes a rare variant of cutaneous lupus erythematosus, frequently mistaken for idiopathic chilblain due to its chilblain-like lesions. To date, no instances of concurrent DN and CHLE occurring at the site of a skin flap or graft have been documented. Herein, we present a case that the occurrence of DN and CHLE developed on a skin flap at once. The simultaneous occurrence of DN and CHLE on a skin flap is exceptionally rare. Clinicians must exercise heightened vigilance due to the common misdiagnosis of CHLE. Various skin disorders can manifest on skin flaps and grafts post-transplantation. Thus, clinicians must remain vigilant for both recurrence and metastasis during post-operative monitoring, while also attending to patients' mental well-being and the condition of skin flaps.