This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psoriasis, Subject name: Dental
The only definite indication for systemic coicosteroids in a case of pustular psoriasis is? 
Select and explain. 
A. Psoriatic Erythroderma with pregnancy, B. Psoriasis in a patient with liver cirrhosis, C. Psoriatic ahritis of moderate degree, D. Presence of extensive lesions
A: Psoriatic Erythroderma with pregnancy
Answer: A: Psoriatic Erythroderma with pregnancy 
Explanation: Systemic coicosteroids - Not recommended for psoriasis, because the disease tends to recur in more severe form after cessation of therapy. Have sho term effectiveness. Can be used in extensive or severe form of generalized pustular psoriasis as a life saving measure when other drugs are contraindicated or ineffective.