<prompt> A 3monthold male infant developed otitis media for which he was given a course of Co-trimoxazole. A few days later, he developed extensive peeling of the skin; there were no mucosal lesions and the baby was not toxic. The most likely diagnosis isToxic epidermal necrolysisStaphylococcal scalded skin syndromeSteven Johnson syndromeInfantile pemphigus  <response>: The extensive peeling of the skin after H0 drug intake makes it look like a case of Toxic epidermal necrolysis or Stevens Jhonson syndrome on the first instance. But it is a case of staphylococcal scalded skin syndrome.Note that all the disease given in the question can cause extensive peeling of the skin.The points which favour the diagnosis of staphylococcal scalded skin syndrome areMucosa is spared in staphylococcal scalded skin syndrome.The absence of toxicity.S.S.S. usually have a primary infection at sites other than skin eg - Nasopharynx, conjunctiva, throat middle ear otitis media.Now, about the individual diseases Staphylococcal scalded skin syndromeUsually begins as prodrome. The acute phase starts with the onset of erythematous rash in the periorbital and perioral area and is tender.These erythematous rashes are soon within hrs or days followed by wrinkling or sloughing of the skin.The sloughing can be provoked by stroking of the skin Nikolskys sign.In a later stage, large flaccid bullae may develop. These bullae can cause loss of water and electrolyte.Fever irritability and lethargy are common but systemic toxicity is not seen.The entire illness resolves within about 10 days.Toxic epidermal necrolysis -It is a severe form of drug reaction.Toxaemia is characteristicIt is characterized by bullae that arise on widespread areas of erythema and then they slough leaving behind raw ulcerated skin.Oral mucosa especially the lips, genital mucosa and conjunctiva are often involved. In some cases, the cornea is also involved leading to corneal opacities.Drugs commonly involved in TEN are Thioacetazone, INH, Sulphonamides, PhenolphthaleinStevens Jhonson syndrome -It is also a severe form of drug eruption.Toxaemia is characteristically present.It is less severe than toxic epidermal necrolysis. In Stevens Jhonsons syndrome bullies and epidermal detachment is seen in 10 of the total surface area. Whereas in TEN it is seen in 30 of the total surface area.The mucous membrane is involvedCommon drugs causing this reaction Sulphonamides, Tetracycline, Oral antidiabetic drugs. 