Can allergy cause acne?what test should i take to know the allergy?

Not an allergy: Forget diet or other environmental exposure as cause for your acne. Treat it. You report being on Clindamycin monotherapy for acne. This is inappropriate; you should never use an antibiotic as solo treatment. If topical benzoyl peoxide and a second medication (retinoid, antibiotic, or the oral contraceptive pill since you are a she) have failed, it is time for a dermatology consult. Best wishes.

No: Allergy does not cause acne.