system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
What is the best time to give oral psoralen with UVA -
assistant
The correct answer is  Ans is 'b' i.e. 1 hour before UVA Oral PUVAo In oral PUVA, 8-MOP is administered orally (0.6 -0.8 mg/kg body weight) 1 -3 hours before exposureo For 5-MOP the usual dose is 1.2-1.8 mg/kg body weight.Topical PUVAo A lotion containing 0.1-1 % 8-MOP is applied on the affected area and is exposed to UVA either immediately or after 1 - 2 hours.o Alternatively, a vanishing cream containing 0.01% TMP is applied 10-20 minutes before exposure.