Hi, You seem to have probably scabies. As there is severe itching more at night and the lesions are on genitals,abdomen and arms. Are you hostelite? This is commonly spreading disease in hostels. Scabies is a contagious disease caused by sarcoptes scabie.Take precaution not to come in contact with other people and infected boys. Wash the bed sheet,towel and your clothes in hot water. If were my patient I would have advise to apply permethrin 5% cream from neck to toe at night at night once a week for few weeks. To Take ivermectol 12 mg single dose. To relieve itching antihistaminics like levocetirizine. I hope this would be helpful to you. Thanks. Dr. Ilyas Patel MD