Small particles on the back are considered to have the following disease possibilities: 1, folliculitis, the appearance of folliculitis papules or acne-like rashes. This disease is mainly due to endocrine disorders, Propionibacterium acnes infection causing hair follicle mouth corkscrew, hair follicle sebaceous gland duct blockage, the contents of the normal metabolism can not lead to sludge, resulting in local inflammatory reaction; 2, eczema, mainly due to allergies, suffering from serious medical diseases, drug allergies or sun ultraviolet radiation allergy caused by. In clinical treatment, you can take oral loratadine capsules and apply topical mometasone furoate ointment, and you need to avoid alcohol and spicy and irritating foods during treatment.