Itchy arms and long and acne like things may be caused by contact dermatitis, eczema, folliculitis and other diseases.
1. contact dermatitis: due to direct contact of the skin and mucous membranes with some exogenous stimulants or allergens caused by inflammation or allergic diseases, typical manifestations of skin rashes, such as arm skin polymorphic rashes, can be erythema, blisters, pimples and so on.
2. Eczema: may be due to immune dysfunction or environmental factors stimulate the formation of inflammatory skin diseases, acute skin can be manifested as erythema, edema, vesicles oozing, etc., chronic skin can become rough and hypertrophic.
3. Folliculitis: that is, due to bacterial and other pathogens infected hair follicles caused by follicle inflammation, the main manifestation is the hair follicle as the center of the red papules, pustules, etc..
Itchy and long arm acne, you can first observe, but if the symptoms worsen, the scope of expansion, it is recommended to go to the hospital.