What causes small red bumps on the back during winter?

In general, the appearance of small red bumps on the back during winter may be caused by dry skin, keratosis pilaris, cold urticaria, folliculitis, psoriasis, or other conditions. If discomfort occurs, it is recommended to seek medical attention promptly. A detailed analysis is as follows:

1. Dry Skin

During winter, low air humidity and large temperature differences between indoor and outdoor environments can cause rapid evaporation of moisture from the skin surface, leading to dryness and damage of the back skin, triggering mild inflammatory reactions and resulting in red bumps. It is recommended to apply a gentle, non-irritating moisturizer or lotion to increase skin hydration.

2. Keratosis Pilaris

In winter, reduced sebum production causes the stratum corneum around hair follicles to become dry due to lack of oil, making it easier for pores to become clogged and form red bumps. It is recommended to exfoliate regularly, wear soft and breathable clothing, and avoid excessive friction or skin irritation.

3. Cold Urticaria

A sudden drop in temperature during winter may trigger an abnormal immune response when the skin is abruptly exposed to cold environments, causing the release of inflammatory mediators and leading to cold urticaria. This results in localized blood vessel dilation and the formation of small red bumps. Symptoms may also include itching, stinging, and, in severe cases, difficulty breathing. It is recommended to wear warm clothing, avoid prolonged exposure to cold environments, and, if necessary, take medications such as cetirizine hydrochloride tablets, loratadine tablets, or compound acetic acid dexamethasone cream under medical guidance to relieve symptoms.

4. Folliculitis

Folliculitis is an inflammatory condition of the hair follicles and surrounding tissues caused by bacterial infection. In winter, inadequate cleansing of the back skin increases the risk of developing folliculitis, presenting as small red bumps. It may also be accompanied by pain and itching; in severe cases, symptoms such as fever and headache may occur. It is important to maintain skin cleanliness, avoid scratching, and use anti-inflammatory and antibacterial treatments such as amoxicillin capsules, erythromycin ointment, or mupirocin ointment under a doctor’s supervision.

5. Psoriasis

Psoriasis is a condition caused by immune system dysfunction leading to abnormal proliferation of skin keratinocytes and inflammatory reactions. In winter, dry climate can further impair the skin barrier, resulting in red bumps on the back and other areas of the body. Symptoms may also include scaling, itching, and pain; in severe cases, joint involvement may occur. It is recommended to keep the skin well-moisturized and avoid contact with irritants. Under medical guidance, topical treatments such as tretinoin cream, tacrolimus ointment, or calcipotriol cream can be used to control inflammation and reduce red bumps.

To alleviate the occurrence of small red bumps on the back during winter, it is advisable to maintain healthy lifestyle habits and a positive mindset, keep the skin hydrated, and pay attention to staying warm and protected from the cold.