What causes small red bumps on the arm?

In general, small red bumps on the arms may be caused by puberty, seasonal skin sensitivity, eczema, urticaria, or folliculitis. It is recommended to seek medical attention promptly, identify the underlying cause, and receive appropriate treatment under the guidance of a healthcare professional. Specific analyses are as follows:

1. Puberty

Hormonal changes during puberty, particularly increased levels of androgens, may stimulate sebaceous glands to produce excess oil. When this oil mixes with dead skin cells on the arms, it can clog hair follicles and trigger an inflammatory response, leading to the formation of small red bumps. Maintaining good personal hygiene habits in daily life can help alleviate symptoms.

2. Seasonal Skin Sensitivity

Individuals with sensitive skin may experience irritation due to seasonal changes—such as pollen in spring or dry, cold air in winter—resulting in small red bumps on the arms. During seasonal transitions, avoiding known allergens and using moisturizers to keep the skin hydrated can help reduce symptoms.

3. Eczema

Eczema is a common skin condition associated with genetic and immune system factors, among others. It may cause chronic inflammation of the skin, leading to small red bumps on the arms. Patients may also experience intense itching and rash. Treatment options include topical betamethasone acetate lotion, loratadine tablets, and triamcinolone acetonide urea cream, used under a doctor’s supervision.

4. Urticaria (Hives)

Urticaria is a common allergic skin reaction. When the body encounters an allergen, it releases inflammatory mediators such as histamine, increasing blood vessel permeability and causing swelling and small red bumps on the arms. Symptoms typically include itching, a burning sensation, and the appearance of red bumps. Medications such as cetirizine hydrochloride tablets, calamine lotion, and chlorpheniramine maleate tablets may be used as directed by a physician.

5. Folliculitis

Folliculitis is a skin condition caused by inflammation of hair follicles. When follicles become infected with bacteria, surrounding skin tissue may become inflamed, resulting in redness, pain, and small red bumps on the arms. Common symptoms include tenderness, swelling, and the presence of red bumps. Treatment may include oral antibiotics such as cephalexin capsules or amoxicillin capsules, and topical mupirocin ointment, used under medical guidance.

In daily life, avoiding known allergens, staying well-hydrated, maintaining a balanced diet, and ensuring adequate rest can help support overall skin health.