Is it allergy to bites??

Patient: Hi, My sister ‘s suffering from a hypersensitivity against insects bites .. She got some ointments like hydrocortizone, some anti-histaminics .. but she doesn’t show any improvement .. I’m just asking you what’s your recommendations for this case ??Now these bites are driving my sister crazy .. sometimes she cries .. I don’t know what to do .. help me please

Doctor: