What causes many small red pimples on the chest and shoulders, and how should they be treated?

Small red pimples appearing on the chest and shoulders are usually caused by excessive sweating with inadequate cleansing, clothing irritation and friction, bacterial folliculitis, common acne, or eczema. It is recommended to seek medical advice promptly, identify the underlying cause, and then improve the condition under a doctor's guidance through general care, medication, and other treatments. Specific causes are analyzed as follows:

1. Excessive sweating and delayed cleansing: During summer or after exercise, heavy sweating mixes with sebum and dirt, clogging pores and promoting bacterial growth, leading to small red pimples. Wash the chest and shoulders with lukewarm water within one hour after exercising, use a gentle body wash, avoid vigorous scrubbing, and dry the skin thoroughly afterward to keep it dry.

2. Clothing irritation and friction: Wearing tight-fitting or synthetic fabrics can frequently rub against the skin, damaging the skin barrier and triggering small red pimples. Switch to loose, breathable cotton clothing; use fragrance-free detergents when washing clothes to prevent residue that may irritate the skin, and reduce friction between clothing and affected areas.

3. Bacterial folliculitis: Inflammation caused by Staphylococcus aureus infection of hair follicles, presenting as small red papules, sometimes with white pustules at the tips. Patients should follow medical advice to apply topical medications such as mupirocin ointment, fusidic acid cream, or compound polymyxin B ointment. Avoid squeezing pimples to prevent spreading the infection.

4. Common acne: Hormonal fluctuations and excessive sebum production lead to clogged pores, forming red pimples on the chest and shoulders, possibly accompanied by blackheads or whiteheads. Maintain a light diet, reduce intake of high-sugar and high-fat foods, use medications such as adapalene gel, clindamycin gel, or tretinoin cream as directed by a doctor, and maintain regular sleep patterns avoiding late nights.

5. Eczema: Skin inflammation triggered by allergies or humid environments, manifesting as clusters of small red bumps with itching. Avoid allergens such as pollen and animal dander, keep living areas dry and well-ventilated, use prescribed topical treatments like hydrocortisone butyrate cream, desonide cream, or mometasone furoate cream, and avoid scratching the affected skin.

In daily life, eat more fresh vegetables and fruits to supplement vitamins and enhance skin resistance. Avoid frequently touching affected areas and minimize external irritation. With proper skincare and treatment, the skin on the chest and shoulders can recover and return to health.