A normally healthy man aged 28 years presented with rash on his arms, legs and face, and painful ulceration of his lips and mouth along with fever. History revealed that he had developed an acute sore throat and conjunctivitis for which he consulted his general practitioner (GP). A diagnosis of acute pharyngitis was made, presumed streptococcal, and oral penicillin was prescribed. What type of hypersensitivity reaction does the above condition is: -

This is a case of Steven Johnson syndrome with the classical targetoid lesions. In Stevens- Johnson syndrome, lesions involve not only the skin but also the lips and oral mucosa, conjunctiva, urethra, and genital and perianal areas. On histologic examination, the "targetoid" lesions show a superficial perivascular, lymphocytic infiltrate associated with dermal edema and accumulation of lymphocytes. These are along the dermo-epidermal junction, where they are intimately associated with degenerating and necrotic keratinocytes, a pattern termed interface dermatitis. It is a type of type 4 hypersensitivity reaction. Treatment approved are: - Steroids IVIg Cyclosporine Etanercept Image A shows Type 1 hypersensitivity reaction Image B shows Type 2 hypersensitivity reaction Image C shows Type 4 hypersensitivity reaction