The terms eczema and dermatitis are synonyms that refer to an inflammatory response of the skin with pathological changes in the epidermis and dermis, with characteristic symptoms and microscopic findings. Dr. Gimeno Carpio, Dermatologist in Valencia, talks about these skin alterations and their treatment.
What is eczema
The alterations that occur in the skin vary according to the intensity and the time of evolution of the eczema. In acute forms, redness (erythema), swelling (edema), small elevations of liquid content (vesicles), exudation and crusting and, occasionally, itching or pruritus can be observed. In chronic forms what we see is erythema, thickening of the skin, scaling and itching.
Causes and types of eczema
Eczema has various causes and two types of eczema can be distinguished according to these causes:
- Endogenous eczemas are those of internal origin, among which we can distinguish three types: seborrheic, dyshidrotic and atopic.
- Exogenous eczemas are those produced by external contact with a substance and are therefore called contact eczemas. Among these we can find two types of eczema: irritative and allergic.
Seborrheic eczema is characterized by the appearance of reddish patches covered by greasy-looking scales in areas rich in sebaceous glands (centrofacial, eyebrows, hairline, centrothoracic, retroauricular) and which do not usually cause itching.
Dyshidrotic eczema is a dermatitis located on the lateral sides of the fingers, palms and soles, whose elementary lesion is the vesicle and which is usually accompanied by intense itching.
Atopic eczema is an intensely pruritic inflammatory process of the skin that occurs in outbreaks in patients with a personal or family history of atopy: eczema, asthma, conjunctivitis or rhinitis. This eczema begins at an early age, six out of ten patients manifest it in their first year and eight out of ten in the first five years. This type of eczema usually resolves spontaneously with age. These lesions begin as small reddish raised skin lesions with or without fluid, which erode and crust over when scratched, with a predilection for the front of the elbows and knees.
In irritative contact eczema, the irritant substances penetrate the skin and alter the epidermal cells, the effect depending on the concentration of the irritant, which will vary from patient to patient. As it is not mediated by immunological mechanisms, lesions may appear immediately after the first contact with the causative substance. Whereas in allergic contact eczema, as it is mediated by delayed allergy mechanisms, lesions appear 48-72 hours after contact with the causative substance and never after the first contact. In these cases it is necessary that the organism has been previously sensitized to the triggering substance.
Contact eczemas are easier to prevent than endogenous eczemas, it is sufficient to avoid contact with the causative substance once it has been identified.
Treatment for eczema
The treatment of these skin disorders will depend on the intensity and extent of the eczema. Depending on this, treatment may be topical, systemic or a combination of both. Corticosteroids are useful, both applied to eczema lesions and administered orally, alone or combined with antibiotics in case of superinfection. In cases accompanied by itching, antihistamines are administered orally. Immunomodulators such as pimecrolimus and tacrolimus topically are also effective.
As general measures, it is recommended to use mild soaps and, when eczema is accompanied by skin dryness, to apply moisturizing creams. It is also important to avoid dry and cold climates, as well as contact with irritating substances such as wool or acrylic and, in case of hand eczema, protection with cotton gloves and rubber gloves on top is very useful.