Small blisters on the buttocks (i.e. buttock blisters) may be diseases such as herpes zoster, insect bite dermatitis and contact dermatitis. 1. Herpes zoster: the disease is caused by the reactivation of varicella zoster virus in the body, which will appear along the distribution of nerves in a band-like distribution of erythema, clustered blisters, accompanied by itching, pain and other symptoms, and blisters rupture after the formation of ulcers. 2. Insect bite dermatitis: after mosquitoes and other insects bite the buttock skin, fusiform edematous masses may appear in the biting area, in which small blisters can be seen, accompanied by intense itching or pain. 3. contact dermatitis: buttocks contact with chemical fiber components of the underwear and other allergens, resulting in the occurrence of allergic reactions, can appear locally erythema, papules, papules, with itching. It is recommended that patients with small blisters on the buttocks go to the hospital in a timely manner, after a clear diagnosis under the guidance of the doctor for standardized treatment.