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
DOC for Psoriatic ahropathy? 
Select and explain. 
A. Methotrexate, B. 5FU, C. PUVA, D. Steroid
A: Methotrexate
Answer: A: Methotrexate 
Explanation: Methotrexate is DOC for Psoriatic ahropathy Psoriatic erythroderma Methotrexate is contraindicated in pregnancy and children. DOC for: Psoriatic ahritis- Methotrexate Erythrodermic psoriasis- Methotrexate Pustular psoriasis- Acitretin > Methotrexate Impetigo herpetiformis- Systemic steroids> cyclosporine