Hello, In some patients though rare in occurrence side effects of ciprofloxacin causes rashes and skin allergy. You can consult his treating doctor and talk about the side effects so that the medicine can be changed and another can be given that suits him better. It can also be due to contact dermatitis or allergy. He is suggested to take antihistamine at bed time, for three days. It should clear his symptoms of allergy and throat soreness. He can take analgesics to reduce soreness and pain. He can apply ointment hydrocortisone on the area affected to reduce itching. He is advised not to scratch, touch or pick at the area affected, it will cause the spread. He should maintain hygiene. Take regular bath and wash all his clothes & bed sheets in hot water frequently. He should not share his clothes, towels, toiletries with anyone. He should be cautious of food intolerance as it can trigger symptoms. He should avoid getting exposed to excessive heat, dander, pollen, dust, etc. Avoid taking alcohol, drugs, stay away from smoking. He can gargle your throat with warm water and salt. Take sips of water whole day. Keep cough lozenges in your mouth to stop coughing. Stay well hydrated. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician