SJS is a severe, most often drug related, rash characterised by extensive flaccid blisters which then merge to form sheets of epidermal detachment with necrosis involving both skin and mucosal surfaces (mouth/ eyes/ genitals). SJS is thought to form part of the same spectrum as TEN with SJT involving <10% body surface area and TEN involving >30%. In SJS/TEN, Nikolsky sign is positive i.e. blisters/ erosions appear when skin is gently rubbed.
Cellulitis is a common bacterial infection of subcutaneous tissue and lower part of the dermis. It is characterised by localised erythema, painful, swollen skin, and systemic symptoms e.g fever.
