Lichen planus is a chronic benign, self-limited disease, which can affect, separately or simultaneously the skin, the scalp, the nails, and especially the mucous membranes (oral, nasal, laryngeal, esophageal, conjunctival, anal and genital). The location of lichen planus is important because, according to this, the quality of life and the psyche of the patient can be affected.
Lichen Planus Causes
The causes are not well known, but the following are assumed:
- Is supposed a autoimmune involvement in the basal layer of keratinocytes;
- Association with hepatitis C, chronic active hepatitis and primary biliary cirrhosis, but also with other autoimmune diseases: ulcerative colitis, alopecia areata, vitiligo, dermatomyositis, morfeea, lichen sclera, myasthenia gravis;
- There is a predisposition for lichen planus after the vaccination for hepatitis B, with a period of latency of a few days to 3 months after any of the three injections;
- Certain drugs: beta blockers, methyldopa, penicillamine, inhibitors of angiotensin converting enzyme, sulfonylureas, carbamazepine, quinine, quinidine, gold salts, lithium, NSAIDs (indomethacin, naproxen, ibuprofen, aspirin, etc.).
Disease incidence is low, less than 1%, but there is a risk of malignancy, which varies according to location of lichen planus, the highest grade of malignant transformation in squamous cell carcinoma is owned by the oral and the vulvar lesions. Squamous cell carcinoma can occur at any age, especially between 30-60 years.
Lichen Planus Diagnosis
It is based on clinical examination that reveals:
Skin changes: polygonal, flat and violet papules, some of them are umbilical, with a glossy aspect when are viewed from the side, covered by white, adherent and unistratified scaling. Papules are symmetrically and are characteristic located on the extension part of the limbs and on the anterior part of the radio-carpal joint and are extremely pruritic. Papules may conflict in psoriasiform plaque, with aspect of a white network called Wickham network.
- On the oral mucosa will appear white streaks (with the aspect of porcelain) looking like a line and asymptomatic. This changes may have a long evolution, about 5 years and a increased possibility of malignancy. Men are most affected;
- On the genital mucosa may occur debilitating changes in anatomy, pain and burning. Is indicated the biopsy of any lesion, especially when is suspected squamous cell carcinoma. Evolution of benign lesions to squamous cell carcinoma can occur between 1 and 11 years.
- Hypertrophic lichen planus – papules are large, extremely itchy and are located on the lower limbs, especially on the ankles. Often becomes chronic and after healing may remain residual hyperpigmentation;
- Atrophic lichen planus – is characterized by the appearance of some lesions, usually reminiscences lesions of annular or hypertrophic lichen planus;
- Erosive lichen planus – is observed on mucosal surfaces;
- Follicular lichen planus may present papules which are converging in plagues, a situation more common in women, which can lead to alopecia;
- Annular lichen planus – presents lesions with an atrophic center, lesions that appear usually on the mouth and genital mucosa;
- Linear lichen planus;
- Bullous lichen planus – develops from preexisting lesions on forearms or on oral region;
- Actinic lichen planus – occurs on areas of maximum sun exposure;
- Pigmentary lichen planus – is rare, occurring in patients with a darker skin pigmentation, especially on the face and neck.
Histopathological examination supports the positive diagnosis of lichen planus, biopsy showing in the top layer of the dermis lymphocytes (T helper) and many Langerhans cells.
Evolution. In more than a half of patients, remission of skin lesions is installed within a maximum of 6 months. Skin lesions are accompanied by severe itching and can lead to atrophy and scarring: final scarring alopecia and sever nail injuries. In patients with mucosa changes and severe hypertrophic lesions, there is a tendency to chronicity.
Lichen Planus Treatment
For the cutaneous lichen planus, treatment consist of:
- The first line of treatment is represented by oral antihistamines and flourince dermato-corticosteroids;
- A second choice therapy is the systemic corticosteroid therapy (0.25 – 0.5 mg / kg Predison) for 3-4 weeks if there are no obvious contraindications, and retinoids, 40-80 mg weekly, in intramuscular injection and triamcinolone acetonide, for 6-8 weeks;
- For severe forms of lichen planus, treatment should be intensive, it starts with a topical steroid, then is choosen another treatment option (corticosteroids, cyclosporine, topical and systemic retinoids, immunosuppressants).
For the mucosal lichen planus:
- Topical corticosteroids are the first therapeutic option. Ointments or gels are used because they are hydrophilic and have good oral mucosal absorption, although gels can be irritating. Corticosteroid resistant cases are receiving cyclosporine and retinoids, both topical and oral.
- The patient should stop taking drugs that can trigger the eruption of lichen planus: beta blockers, methyldopa, penicillamine, inhibitors of angiotensin converting enzyme, sulfonylureas, carbamazepine, quinine, quinidine, gold salts, lithium, NSAIDs (indomethacin, naproxen, ibuprofen, acetylsalicylic acid, etc.).
- Risk factors must be eliminated: alcohol, smoking, bruxism, sloppy teeth, inadequate dentures, especially in the case of oral lichen planus. Diet should be rich in fruits and vegetables.
In most cases, the prognosis of lichen planus is good, disease can be remitted in 18 months. The treatment is not addressed to a very well known cause, and therefore adverse effects can easily occur.