Lichenification is a reaction of the skin, manifested by thickening of the skin. This disease appears as a reaction to repeated and prolonged scratching. What are the reasons the skin reacts by thickening or hardening? What are the possible treatments ?

Lichenification is a thickening of the skin in patches of pinkish-bistre then brown color and irregularly crisscrossed by deep furrows. Mode of reaction of the skin, it is due to chronic and local scratching.

It is therefore a frequent consequence of skin diseases such as eczema.

However, lichenification can also appear by scratching tics, without initially itching, in anxious people, on specific areas: neck, ankles, hand, genital area, etc. We then speak of primitive lichenification. It can also appear due to excessive hygiene care. These are psychosomatic illnesses.

A non-painful but annoying symptom, itching or itching of the skin, causes the need for scratching, in a generalized or localized way. Of course, a light, transient itching is perfectly normal, but it becomes abnormal when it is responsible for skin damage due to excessive scratching, or even embarrassing enough to require a consultation.

The reasons for scratching are numerous, and can have both nervous and physiological origins. Sometimes it is impossible to know the true origin of scratching.

First of all, pruritus can be caused by skin conditions:

• Dryness or xerosis;
• Contact eczema (caused by an allergen);
• Atopic eczema (in infants and young children);
• Hives (red patches);
• Psoriasis (red scaly patches);
• Lichen planus (lesions on the hands, feet, wrists and forearms, knees);
• Folliculitis (inflammatory disease of the hairs and their root);
• Seborrheic dermatitis (red patches on the scalp).

 Pruritus can also be caused by allergenic, irritant or environmental factors, in connection with:

• An ingredient contained in a cosmetic;
• Metals contained in jewelry;
• Irritating materials, such as plastic, latex;
• Textiles, dyes or resins that come into contact with the skin;
• Caustics;
• Allergies to certain foods.

Some medicines can also cause itching, such as aspirin, antibiotics, antimalarials, opiates (treating pain) and antihypertensives (beta blockers).

We must also not forget the environmental conditions that can create itching: heat and sun, variations in humidity and temperature. Insects, plants and parasites can also be at the origin (mosquitoes, lice, fleas, bees, nettles, etc.).

Finally, itching is potentially a sign of possible infections: yeast infection, chickenpox, shingles, herpes. They also occur during hormonal changes, such as during pregnancy or after menopause.

Lichenification is secondary in cases of associated pruritic dermatosis (psoriasis, lichen sclerosus). These are lesions caused by repeated and prolonged scratching of patches of eczema or psoriasis. In all cases, there is skin thickening: the skin thickens to defend itself. Pink then brown scratching lesions appear, with an accentuation of the normal grid pattern of the skin.

On the skin appears a developed and hyperpigmented plaque, in variable proportions, but well delimited. With exaggerated skin lines and a thickened appearance, these plaques are characteristic of lichenification. These plaques are itchy, dry, scaly, oval or angular in shape. They appear on the legs, arms, neck, upper trunk, and anal area.

The treatment is based on:

• Treatment of pre-existing dermatosis;
• Supportive psychotherapy, tranquilizers;
• Local corticosteroid therapy.

An underlying cause can be treated first (stress, irritation, allergies, etc.). Then we will treat with a strong topical corticosteroid for 2 to 4 weeks, until the skin condition returns to normal. The treated pruritus normally goes away within a few days. It is advisable to hydrate with emollient and non-allergenic creams.

It is advisable to consult when the scratching becomes recurrent and the skin too painful, affected by numerous dry and scaly patches. Be careful not to wait too long before consulting because we then enter a vicious circle of chronic scratching leading to additional itching.