The common causes of itchy bumps on the back include tinea corporis, malassezia folliculitis, eczema, and so on. 1. ringworm: this disease is caused by dermatophyte infection, common causative organisms include Trichophyton rubrum, Trichophyton intermedius, etc., which manifests itself as pimples, blisters, pimples, macules, scales, hyperpigmentation, itchiness and other symptoms on the skin. 2. Malassezia folliculitis: this disease is caused by Malassezia infection of the superficial cuticle and follicular inflammatory damage, is a fungal skin disease, in specific conditions, such as excessive sweating, oily skin, decreased immunity, etc., easy to induce this disease. It manifests itself in the form of follicular papules, papules or small pustules, hemispherical, itchy, aggravated by sweating and other symptoms on the skin. 3. Eczema: the etiology of eczema is not clear, may be related to the back of the skin for a long time in a hot and humid or dry environment, chemical stimulation, some chronic disease factors. The manifestation of the skin with erythema, papules, papules, blisters, vesicles, itching and other symptoms. It is recommended that patients go to a regular hospital, after a clear diagnosis, follow the doctor’s instructions and reasonable treatment, to avoid delaying the condition, usually pay attention to skin hygiene and cleanliness.