000036 - Pembrolizumab induced Stevens-johnson syndrome in non-small cell carcinoma of lung

A 67-year-old male presented with a generalized rash. He had undergone two cycles of chemotherapy with a pembrolizumab and paclitaxel-carboplatin regimen for squamous cell carcinoma of the lung. Fever, rash, and mouth pain developed eight days after the second cycle of the regimen. Physical examination revealed conglomerated erythematous lesions covering the whole body, including the periorbital area, lips, neck, trunk, and upper and lower extremities. Numerous lesions consistent with erythema multiforme were observed. The rash was particularly severe, with bullous formation on both anterior legs, though Nikolsky's sign was absent. Blisters on the lips rapidly ruptured, forming erosions that severely hindered the patient's ability to eat and drink. A skin punch biopsy from the right leg revealed hyperkeratosis and spongiosis, intra-epidermal vesicles, abscess formation and necrosis in the epidermis, and perivascular lymphocytic and eosinophilic infiltration in the dermis. The patient was treated with intravenous methylprednisolone, which was gradually tapered, along with antihistamines and topical steroids. Intravenous immunoglobulin (IVIG) was administered (60g/day for 3 days). As systemic steroids were tapered, the patient's general condition improved, and the skin lesions completely resolved after three weeks. Chemotherapy was discontinued. The patient maintained a state of stable disease for one year, after which the lung cancer increased in size again, and chemotherapy was administered with only paclitaxel and carboplatin, excluding pembrolizumab. The patient did not have a recurrence of skin lesions during the chemotherapy. After 3 cycles of treatment, the patient is currently in a rest period due decreased performance status.