Is perspiration a triggering factor for psoriasis?

Perspiration (sweating) is a natural physiological phenomenon. It is characterised by the secretion of sweat by the sweat glands. Controlled by the hypothalamus, perspiration is activated in response to the body's need to lower its temperature in the face of intense heat, high physical activity or a stressful situation. It also reflects our emotions.

Sweat can cause skin irritations, particularly on psoriasis lesions. It can lead to burning or tingling sensations due to its natural acidity, with a pH ranging between 4 and 6. Furthermore, sweat contains sodium chloride, otherwise known as salt, which has a drying effect on the skin. When salt comes into contact with the skin, it can absorb moisture from the skin's surface, leading to a faster evaporation of water present in the upper layers of the skin. This can result in temporary skin dehydration, leaving a feeling of dryness. Skin dryness exacerbates psoriasis, as the hydrolipidic film is altered, and the skin is inherently less protected against external aggressions and allergens.

Currently, there are no scientific studies that assert that psoriasis could be triggered by perspiration. However, it could potentially be a factor that exacerbates the condition. Indeed, perspiration creates a moist environment conducive to the proliferation of bacteria such as staphylococci. These can infect existing psoriasis lesions. This can lead to secondary bacterial infections such as impetigo, folliculitis or abscesses.

It is impossible to completely halt perspiration. However, it is possible to limit the effects of sweating.

• Exercising with caution during physical activities: Engaging in sports is not discouraged for individuals with psoriasis. However, it is recommended to take a shower immediately after physical activity to remove sweat.

• Wearing loose and cotton clothing: Synthetic fibres and tight clothing are strongly discouraged as they promote sweating. Prioritise natural fibres such as cotton or linen. These fabrics allow better air circulation, thus helping to remove moisture and reduce perspiration.

• Avoid stressful situations: stress tends to induce excessive sweating. When you are stressed, your body releases hormones such as adrenaline, which stimulate the sympathetic nervous system. The activation of the sympathetic nervous system then triggers several physiological reactions, including the stimulation of the sweat glands which are responsible for sweat production.

• SAURAT J. & al. Dermatologie et infections sexuellement transmissibles (2016).

• TENG Y. & al. Infection-provoked psoriasis: Induced or aggravated (Review). Experimental and Therapeutic (2021).