Cefalexin

A 53-year-old woman developed toxic epidermal necrolysis (TEN) as an adverse reaction to cefalexin, a cephalosporin antibiotic, which she was taking for erythema and swelling of the left knee. Symptoms began on the second day of treatment and included diffuse, pruritic erythema, bullae on the legs and body, positive Nikolsky's sign, confusion, tachypnea, and decreased lung function, with a high temperature and abnormal blood values. Biopsy results confirmed eosinophilic necrosis of the epidermis and subepidermal bullae, with no evidence of bacterial or viral infection. After three months of treatment with silver sulfadiazine cream, the patient's condition improved, leaving only Beau's lines and moderate telogen effluvium. This case, reported in the Journal of the American Academy of Dermatology, highlights the potential for cephalosporin antibiotics to cause severe skin reactions like TEN.