The causes of itchy buttocks scratched up a lot of bumps include eczema, mosquito bites, ringworm, etc. The ointment to be smeared includes hormonal ointment, anti-bacterial ointment, anti-fungal ointment and so on. 1. Eczema: If eczema, you can apply glucocorticoid ointment such as Eloxon ointment and other anti-inflammatory treatment. 2. Mosquito bites: mosquito bites generally do not need to apply ointment treatment, serious cases can also be given glucocorticoid ointment treatment. 3. ringworm: if ringworm, perfect fungal examination, you can apply ketoconazole cream and other drugs antifungal treatment. Finally, the phenomenon of itchy buttocks scratched up a lot of pimples, please consult a doctor in time for symptomatic treatment.