What is lichen simplex?
Lichen simplex is is also called neurodermatitis. This localised type dermatitis or eczema follows repeated rubbing or scratching. The stimulus to scratch may be an existing skin condition such as atopic eczema or psoriasis, a compressed nerve leading to the skin (neuropathic itch or pruritus), or in some cases a bad habit.
Lichen simplex tends to be very persistent, and readily recurs despite often initially effective treatment.
What does lichen simplex look like?
Lichen simplex presents as a very itchy and thickened single patch of skin or a group of small firm papules (bumps).The skin markings are prominent, and the hairs are often broken-off. The colour may be darker or sometimes paler than the surrounding skin. It is most often unilateral, i.e., it is found only on one side of the body, but sometimes both sides are affected.
What areas are prone to lichen simplex?
Lichen simplex can affect any part of the skin. The nape of the neck, the scalp, the shoulder, the wrist, and the ankle are common sites. Lichen simplex can also affect anal or genital skin. The labium major or outer lip of vulva is the most common genital site for lichen simplex in women. The scrotum is a common site fo lichen simplex in men.
What is the treatment for lichen simplex?
This is most important but will need a lot of will-power if the stimulus to itch is very intense. Steroid creams prescribed by your doctor will help. Apply moisturizers or a cold flannel whenever you feel the need to scratch. Pat instead of rubbing. Cut your nails short and use the pulp of your fingers.
As lichen simplex seldom responds to mild topical steroid preparations, potent topical steroids are usually needed. Apply a thin layer of the cream to the thickened skin at night. Continue until the patch has flattened with the normal skin.
Your doctor or dermatologist may suggest occluding the worst patches by taping them with a plastic cling film wrap at night-time. Do not do this for more than a few days without checking first with your doctor.
Note: this treatment may not be suitable for the face, genitals or body folds, as strong steroid creams can cause skin thinning.
Treatment should then be continued with a weaker topical steroid if the itch continues to be bothersome.
Other measures used to treat lichen simplex
- Coal tar preparations can work well to lessen the itching, without any risk of skin thinning.
- Moisturisers should be applied liberally and often, to smooth the skin and reduce itch.
- Avoid soap: try bath oils or soap substitutes.
- Antihistamine pills can lessen itch. They are best taken at night.
- Steroid injections into the patches may be recommended by your dermatologist.
- Phototherapy (ultraviolet light treatment) is worthwhile for those with widespread neurodermatitis.
- Oral corticosteroids, methotrexate, azathioprine or ciclosporin are sometimes necessary for severe widespread lichen simplex.
- Tricyclic antidepressants such as amitriptyline are very useful if there is a neuropathic cause of itch, for example a trapped nerve.
- There are also reports of benefit from selective serotonin reuptake inhibitor antidepressants and gabapentin.