What causes many small bumps to appear on the arm?

Small bumps appearing on the arms are usually caused by dry skin, blocked sweat glands, urticaria, folliculitis, psoriasis, or other conditions. If discomfort occurs, it is recommended to seek medical attention promptly. Specific causes are analyzed as follows:

1. Dry Skin

In dry seasons or when moisture is lacking, the skin tends to become dry and the stratum corneum thickens, leading to small bumps on the arms. Keep the skin clean and use moisturizing products such as lotions or creams containing glycerin, hyaluronic acid, etc., to lock in moisture and relieve dryness.

2. Blocked Sweat Glands

During hot summer months or after physical exercise, excessive sweating may block sweat glands, preventing sweat from being excreted normally and resulting in numerous small bumps on the arms. Maintain good personal hygiene, bathe regularly, and use gentle cleansers to keep the skin clean.

3. Urticaria

Urticaria is generally triggered by external stimuli or allergen exposure. Cold stimulation, sunlight exposure, and similar factors can induce urticaria, increasing vascular permeability in the skin and causing localized tissue swelling, which manifests as multiple small bumps on the arms. It is often accompanied by symptoms such as redness, swelling, and itching. Patients may take medications such as cetirizine tablets, loratadine tablets, or dexamethasone tablets under medical guidance.

4. Folliculitis

Folliculitis is commonly caused by bacterial infection. When hair follicle openings on the arms become blocked, bacteria multiply within the follicles, triggering an inflammatory response that may lead to redness, swelling, and rashes around the follicles, resulting in numerous small bumps. Symptoms may include pain or pus formation. Treatment should follow a doctor's advice and may include antibiotics such as cefuroxime axetil capsules, doxycycline hydrochloride tablets, or cephalexin capsules.

5. Psoriasis

Psoriasis is associated with abnormal activation of the immune system, which may cause excessive growth and differentiation of skin cells, forming red plaques and scales. Small bumps on the arms could be an early sign of psoriasis. Other symptoms may include erythema, scaling, itching, and joint pain. Under a doctor’s supervision, patients may use topical treatments such as halometasone cream, mometasone furoate cream, or tretinoin cream.

Maintain a healthy diet, avoid spicy and irritating foods, and engage in regular exercise to strengthen the body's immunity.