This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Papulosquamous disorders, Subject name: Dental
The only definitive indication of systemic steroids in psoriasis- 
Select and explain. 
A. Pustular psoriasis, B. Impetigo herpetiformis, C. Psoriatic ahropathy, D. Erythroderma
B: Impetigo herpetiformis
Answer: B: Impetigo herpetiformis 
Explanation: Only indication for use of systemic steroids is generalized pustular psoriasis in pregnancy ( impetigo herpetiformis). IADVL textbook of dermatology page 1049