What causes anal eczema?

Eczema growing anywhere on the body will cause us a lot of discomfort, especially itching. Therefore, when we encounter eczema, we cannot touch the wound with our hands, which can easily aggravate the condition because eczema will spread. If eczema grows on the anus, you should seek medical attention immediately, and you should pay attention to the hygiene of your anus and pants. Now let us understand together what causes anal eczema.

The causes of eczema are very complex, involving the interaction of internal and external factors, and are often multifaceted. External factors such as living environment and climatic conditions can affect the occurrence of eczema. External stimuli such as sunlight, ultraviolet rays, cold, heat, dryness, sweating, scratching, friction, various animal furs, plants, chemicals, etc., and some daily necessities such as balm and other cosmetics, soap, artificial fibers, etc. can induce eczema. Certain foods can also make eczema worse in some people. Intrinsic factors such as chronic digestive system diseases, gastrointestinal dysfunction, mental stress, insomnia, excessive fatigue and other mental changes, infectious lesions, metabolic disorders and endocrine dysfunction can all cause or aggravate the symptoms of eczema.

From the perspective of pathogenesis, eczema is mainly a delayed allergic reaction caused by complex internal and external stimuli. However, its etiology is still not fully elucidated, including the nature of the allergen, the characteristics of the immune response, and whether it is related to IgE-mediated delayed reaction. Patients may have certain qualities, which are dominated by genetic factors and therefore occur in specific people, but are also affected by health conditions and environmental conditions. For example, patients sometimes cannot tolerate many harmless stimuli in their living and working environment, and certain foods can aggravate eczema. Patients are very sensitive and can react positively to many substances in patch tests. Even if certain allergens are removed, the eczema lesions will not disappear quickly. However, some patients can change their body's reactivity through increased exercise and changes in the environment, and no longer develop eczema when exposed to various stimuli that previously triggered eczema. All these illustrate the complexity of its pathogenesis.

It is limited to the skin around the anus and may affect the perineum in a few cases. The itching is unbearable. It is often moist, the skin is infiltrated and thickened, and cracking may occur. In the acute phase, the rash is composed of numerous densely packed millet-sized papules, papulovesicles or small blisters with a flushed base. Due to scratching, the skin lesions may show obvious punctate exudation and small erosions. The center of the lesion is often heavier and gradually spreads to the surrounding area. There are also scattered papules and papulovesicles on the periphery, so the boundaries are unclear. When combined with infection, the inflammation may be more obvious and form pustules, pus oozing out or yellow-green or dirty brown scabs. It may also be combined with folliculitis, furuncle, local lymphadenitis, etc.

Subacute eczema occurs when the inflammation of acute eczema is alleviated, or if the acute phase is not promptly and appropriately treated and is delayed for a long time. The skin lesions are mainly small papules, scales and crusts, with only a few papulovesicles or small blisters and erosions. There may also be mild infiltration, and the patient still feels severe itching.

Chronic perianal eczema may develop due to repeated attacks of acute or subacute eczema, or it may present as chronic inflammation from the beginning. The skin of the affected area is infiltrated and thickened, turning dark red and pigmented, with a rough surface and covered with a small amount of bran-like scales, or scabs due to scratching. Some cases have varying degrees of lichenification, which is localized and has clear edges. There may also be scattered papules and papulovesicles on the periphery. During acute attacks, there may be obvious exudate. The subjective symptoms also include obvious itching, which often occurs in paroxysms. Because the skin loses its normal elasticity and is more active, it may crack and cause pain in the affected area. The course of the disease is uncertain, prone to relapse, and difficult to heal.