Causes and risk factors:
The exact etiology of this condition is not known. Various hypotheses have been put forth. This condition is said to be provoked by scratching. This condition is commonly seen in people suffering from skin disorders like skin allergy, atopic dermatitis, insect bites, scars, or eczema. Mental stress and certain emotions (anxiety and obsession) also play an important role in this. Certain hair dyes which contain a chemical, phenylenediamine, also provoke this condition. Prolonged exposure to pollution in traffic on streets seems to contribute not only in development of several skin infections, but also lichen simplex. Exposure to lithium has also been reported regarding development of this condition.
Clinical presentation:
This condition is commonly seen in areas where one can scratch easily. The common site of affection is scalp, nape of neck, lower extremity, vulva, and scrotum. Appearance of small eruptions (erythema) is seen in initial stage. Later, thickening of skin is seen. Over time, scaling of the affected skin takes place. Formation of plaques can be seen. The size varies from 2-3 cm. It can either be oval in shape or linear. The affected skin becomes dry and scaly. Pigmentation and scratch marks can be seen.
Investigations:
Diagnosis is done on the basis of the symptoms narrated by the patient along with local examination carried out by the dermatologist. Certain investigations are advised which will help to confirm the diagnosis or rule out other similar condition. Histological examination of the skin is done. Skin biopsy can also be recommended. Immunoglobulin E levels are also measured.
Treatment:
If the condition is provoked by some underlying cause, treating it is the main line of treatment. The treatment plan consists of topical application of steroids or cooling and soothing agents. Moisturizers help to relieve the scratching. Coal tar preparation seems to be useful. If needed, steroid injection and oral antihistamines can also be given.
When to contact a doctor:
Contact a dermatologist if one notices any eruptions , complains of itching and scaling of skin.
System involved: Integumentary system.
Organ involved: Skin and tissue
