<prompt> The only indication of giving corticosteroids in pustular psoriasis isPsoriatic erythroderma with pregnancyPsoriasis in a pt. with alchoholic cirrhosisModerate arthritisExtensive lesions  <response>: Indications of systemic steroids in psoriasisGeneralized pustular psoriasis of pregnancyerythroderma only definitive indicationPersistent, otherwise uncontrolled, erythrodernzic psoriasis causing metabolic complications.Generalized pustular psoriasis, if other drugs are contraindicated or ineffective.Severe psoriatic arthritis threatening severe irreversible joint dagmage not in mild or moderate arthritis. Note - Some guides have given option d i.e. extensive lesions as answer. But they are wrong, following statement will clear all doubts :-Systemic steroids are the drug of choice in pregnant women with exfoliative erythroderma elythrodermic psoriasis and generalized pustular psoriasis . I have also confirmed it from many teachers of dermatology.About extensive lesions Extensive lesions are called when greater than 30 of surface area is involved. Treatment of choice for extensive lesions is Narrow band UV-B incombination with emollient. Alternatives are PUVA, methotrexate, Acitretin, Cyclosporin, fumaric acid esters. 