Ans. is 'a' i.e., >90% Erythroderma (generalized exfoliative dermatitis) Erythroderma is the term used when the majority of the skin is erythmatous red color and usually associated with crusts, there may be associated erosions, pustules, shedding of nails or hair. "Exfoliative dermatitis (erythroderma) refers to a scaling erythematous dermatitis involving 90% or more of the cutaneous surface". Exfoliative dermatitis is characterized by : - Erythema Scaling This often obscures the primary lesions, For example in psoriasis teh characteristic lesion is erythmatous plaque with silvery scale, on extensors. When erytherma occurs as a complication, most of the cutaneous surface is involved by erythma which obscures the primary lesions of psoriasis. Causes of Erythroderma (exfoliative dermatitis) 1. Skin disorders Psoriasis Dermatitis/Eczema (atopic, stasis, contact, seborrheic) Pityriasis rubra pilaris Lichen planus 2. Systemic diseases --> Cutaneous T-cell lymphoma 3. Drugs --> Gold, Allopurinol, Phenytoin, penicillin, Sulfonamides. 4. Idiopathic (secondary to solid tumors of lung, liver, prostate, thyroid, colon). Treatment of erythroderma (exfoliative dermatitis) Topical coicosteroids are the primary category of medication used to treat exfoliative dermatitis. A sedative antihistaminic may be a useful adjunct for pruritic patients. Systemic antibiotics may be used if infection is suspected. Systemic coicosteroids may be useful in severe disease for remission induction, but not for maintenance. Systemic coicosteroids should not be used in psoriasis (psoriatic erythroderma); Acitretin or methotrexate are preferred.