- 1 What is lichen planus?
- 2 What are the causes of lichen planus?
- 3 What are the risk factors of lichen planus?
- 4 What are the signs and symptoms of lichen planus?
- 5 Lichen planus can manifest as different variants and they are:
- 6 How is Lichen planus diagnosed?
- 7 How is Lichen planus treated?
- 8 What are the complications of Lichen planus?
What is lichen planus?
Lichen planus is a skin rash which is usually triggered by the immune system. The exact reason for this immune system trigger is not known. However, several factors that may contribute to this immune system trigger is found and the potential causes include:
- Viral infections
- Genetic factors
Sometimes lichen planus can be a result of an autoimmune disorder as well. Lichen planus is a papulo squamous disorder and as explained has a debatable aetiology. It is a pruritic disease affecting the skin, mucous membranes and hair follicles.
Lichen planus is characterized by the formation of tiny, shiny, violaceous flat topped, polygonal, greyish white, purple or lilac papules. The surface shows adherent scales. Sites commonly affected are the front of wrists, shins, trunk, medial thighs and glans penis. The cutaneous lesions are intensely pruritic and the lesions on legs may become hypertrophic. The oral mucosal lesions of Lichen planus may be reticular, annular, atrophic, or erosive. The buccal mucosa is commonly affected even though tongue and gingiva may also be involved.
Anyone can get this but it has been found that lichen planus tends to be common among the middle aged people of both sexes.
Lichen planus in most of the cases is not a serious condition and it is not a contagious disease as well. However, having this dermatological sin condition is very uncomfortable to the affected person.
What are the causes of lichen planus?
The exact cause of lichen planus is still not known. However, it may either be bacterial or viral in origin. Immunologic factors are also implicated due to the presence of consistent immunofluorescence pattern. It may also follow bone marrow transplantation or graft versus host reaction. Furthermore, certain individuals are genetically predisposed to it. Also several drugs such as chloroquine, quinacrine, streptomycin, paraaminio salicylic acid (PAS), methyldopa, quinidine, phenothiazine, chlorpropamide, gold, bismuth, levamisole, and penicillamine are implicated. Exposure to paraphenylenediamine salts encountered in colour photographic developer may also produce these lesions.
What are the risk factors of lichen planus?
Anyone can develop lichen planus but there are some factors that make a person more likely to develop lichen planus when compared to others. Both men and women are affected equally especially the skin form of lichen planus. However, the oral form of lichen planus tends to affect women twice as more as the males. Other risk factors of lichen planus include:
- Family history of lichen planus
- Viral diseases such as hepatitis C
- Exposure to certain chemicals
- Those who are on certain drugs such as chloroquine, quinacrine, streptomycin, paraaminio salicylic acid (PAS), methyldopa, quinidine, phenothiazine, chlorpropamide, gold, bismuth, levamisole, and penicillamine
- Exposure to paraphenylenediamine salts encountered in colour photographic developer.
What are the signs and symptoms of lichen planus?
It is characterized by the formation of flat topped, polygonal, greyish white, purple or liliac papules. Its surface is scaly. The surface is also traversed by fine white lines known as the ‘Wickham’s striae. These striae become prominent after the application of an emollient. The papules may coalesce to form plaques. The papules may be scattered or grouped.
Lichen planus also exhibits the Koebner’s phenomenon. The Koebner’s phenomenon is also known as a isomorphic response and refers to the appearance of the lesions over a site of injury.
Lichen planus tend to involve the flexor surfaces of the wrist and forearms, lumbar area, ankles glans penis, anterior aspect of lower legs, and the dorsal surfaces of the hands. These cutaneous lesions usually disappear by about 6 months in more than half of the affected patients and in about 85% of the affected patients, these lesions take about 18 months for the lesions to disappear.
Lichen planus not only involves the skin surface, but other structures may also be involved such as the:
- Mucous membranes
Mucosal surfaces are involved in nearly half the patients. The buccal mucosa and the tongue are most frequently affected but the lips, gums, palate, conjunctivae, larynx, genitalia, and gastrointestinal tract may also be involved. The mucosal lesions consist of lacy, reticulated, white streaks, papules, plaques, and erosions.
Chronic disease with lichen planus is commonly seen with oral lichen planus or with large, annular hypertrophic lesions and also with the involvement of the mucous membranes.
Chronic erosive oral lichen planus may predispose to squamous cell carcinoma.
Nearly 25% of the males with lichen planus show involvement of their penis as well. These lesions typically appear over the glans penis and they are typically popular and arranged in an annular fashion. Occasionally,
the glans penis may have erosive lesions.
Changes in the nails
Nail changes in Lichen planus is only seen in 10% of the patients who are affected with this disease. The nail changes that are commonly seen with Lichen planus include the following:
- Thinning of the nail plate
- Ridging and splitting in the longitudinal axis
- Onycholysis – This is a common nail disorder and it refers to the separation of the finger nail or the toe nail from their nail bed.
- Subungual hyperkeratosis – Once there is separation of the nail from its nail bed (that is onycholysis), there is a space created in between and this space is build-up of soft yellow keratin.
- Red or brown discoloration of the nail plate
- Pterygium – This is a hall mark feature of Lichen planus. Here, the proximal nail plate is lost due to the fusion of the proximal nail fold with the nail bed.
Lichen planus can manifest as different variants and they are:
- Annular lichen planus
- Linear lichen planus
- Hypertrophic lichen planus ( Lichen verrucosus)
- Atrophic lichen planus
- Vesiculobullous lichen planus
- Lichen planus actinicus
- Lichen planus erythematosus
- Lichen planopilaris
- Ulcerative lichen planus
- Twenty nail dystrophy (TND)
Annular lichen planus
This variant of lichen planus presents as a ring of typical lichen planus papules and tends to spread peripherally producing a central clearing.
Linear lichen planus
This variant of lichen planus consists of typical lichen planus lesions which are distributed in a linear fashion. However, occasionally It may show a zosteriform distribution. This means that the appearance is similar to that of a varicella zoster distribution which usually follows a dermatomal distribution.
Hypertrophic lichen planus (Lichen verrucosus)
This form of lichen planus typically arises over the shin, ankles and the soles of the feet. It is intensely pruritic in nature, lichenified, scaly, violaceous, and has an appearance of verrucous (wart like) hyper pigmented plaques. These lesions are often symmetric and chronic.
Atrophic lichen planus
This type of lichen planus occurs over the mucous membranes. Atrophic lichen planus may produce white atrophic spots and these lesions have to be differentiated from lichen sclerosus et atrophicus and guttate morphea.
Vestobulbous lichen planus
This variant of lichen planus may arise over the pre-existing lesion of lichen planus or may occur as new lesions (de novo). Due to basal cell degeneration, there is separation at the dermo epidermal junction. The clinical presentation is similar to that of lichen planus pemphigoides and therefore should be differentiated from each other.
Lichen planus actinicus
This variant is usually encountered in tropics, on sun exposed areas. These lesions are pigmented, dyschromic and are only mildly itching.
Lichen planus erythematosus
This variant of lichen planus is usually seen in the elderly patients and typically presents with soft, red papules usually over the forearms and are not itching.
This form of lichen planus also presents with follicular papules which are hyperkeratotic but they usually appear over the scalp. The area which is usually affected shows scaling over the lesions. Sometimes alopecia is associated with these lesions. There is another variant of lichen planopilaris known as Grahm Little-Piccardi-Lassueur syndrome. This syndrome consists of scalp aloplecia, alopecia of the axilla and groin and follicular keratotic lesions of the skin.
Ulcerative lichen planus
As the name suggests, ulcerative lichen planus consists of ulceration over the soles of the feet and of the buccul mucosa. This is also associated with alopecia and loss of toe nails. Lichen planus lesions may be found over other parts of the body as well and this is a typical presentation. Usually, the lesions that appear over the feet are very painful. Ulcerative lichen planus may predispose one into the development of squamous cell carcinoma.
Twenty nail dystrophy (TND)
Twenty nail dystrophy has been given another name called as trachyonychia and this condition was described nearly 20 years ago. This condition is characterized by alternating elevations and depressions of the nails, also known as longitudinal ridging, pitting of the nails, roughening similar to sandpaper, splitting and a colour change to muddy greyish white colour. Dystrophy of all 20 nails is a prominent feature in this condition.
This condition commonly affects infants and children, but occasionally adults may also be affected. Although this condition has been sparingly reported, it is a very well recognized condition and its diagnosis is purely clinical made on the basis of clinical features. Diagnosis can be confirmed with the microscopic pathology. This is a self-limiting condition and only occasionally requires any form of intervention.
Acute lichen planus usually resolves in 6 to 18 months. The lesions heal leaving behind hyperpigmentation which may take years to resolve. Chronic lichen planus persists for a long period. Oral lichen planus, hypertrophic lichen planus, and lichen planopilaris tend to be chronic.
How is Lichen planus diagnosed?
Lichen planus is a condition that can be diagnosed clinically. However, some cases may need confirmation with histopathology reports. During histopathology, the pathologist will look for certain features that may characterize the presence of lichen planus. The following features may suggest that there is lichen planus:
- Irregular acanthosis producing a saw tooth appearance of the rete ridges
- Liquefaction degeneration of the basal cell layer
- Focal hypergranulosis (This is the focal thickening of the granular later)
- The upper dermis shows lymphocytic infiltrations forming a band like appearance.
- Incontinence of melanin
- Colloid bodies which are situated deep within the dermis. The lower epidermis may show degenerative keratinocytes which are known as colloid or civatte bodies.
- A Max Joseph space – This is a small space that is found between the dermis and the epidermis.
Laboratory studies such as direct immunofluorescence study in lichen planus can be done and It may show that there are global deposits of immunoglobulin M (IgM) and also may show that there are complement mixed with apoptotic keratinocytes.
There are no imaging studies which are necessary or useful for the diagnosis of Lichen planus.
How is Lichen planus treated?
Lichen planus tends to resolve on its own after a varying period of time. However, some forms of Lichen planus may produce disturbing symptoms such as pain, burning sensation over the lesions, redness, blister formation, sores or ulcers and such cases therefore requires symptomatic treatment. Mild cases of Lichen planus are usually given only symptomatic treatment. This means, the symptoms are managed.
Since itching is one common complaint in patients with Lichen planus, antihistamines may be prescribed to relieve the pruritus.
Topical application of topical corticosteroids is also helpful owing to their anti-pruritic and anti-inflammatory effects.
Severe cases of Lichen planus, especially patients with the involvement of the scalp, nail, and mucous membranes may require more extensive treatment. Corticosteroid pills such as prednisone or corticosteroid injections may help with the severe cases of Lichen planus. Griseofulvin may also be beneficial in the severe cases of Lichen planus. Oral Lichen planus responds to topical application of corticosteroid. Oral lichen planus can lead to gum disease as well and therefore it is extremely important that you brush and floss your teeth regularly as advised by your dentist. Following oral lichen planus, regular check-ups with your dentist at least twice a year is a must.
Other methods of symptomatic treatment available for Lichen planus include:
- PUVA therapy – This is a form of light treatment which will help to clear your skin.
- Retinoic acid – This application is applied over the skin with the lesions of Lichen planus. Sometimes, this drug is given as an oral preparation to be taken orally and will help to clear the skin.
What are the complications of Lichen planus?
- Discomfort and pain during sexual intercourse – This is extremely true if you have lichen planus which has developed over the vagina or vulva and such lesions are usually difficult to treat and therefore can lead to pain and discomfort during sexual intercourse.
- Squamous cell carcinoma – Although the risk of developing squamous cell carcinoma is very small, this is the last thing you would want to have. Therefore you should consult your dermatologist for regular skin cancer examination.
How can you avoid the Lichen planus from getting worse? – Tips to control your lichen planus.
Here are a few tips that may be helpful for you all to prevent the lichen planus from getting worse:
If you have the lesions on the skin:
- Reduce your stress level because stress tends to make lichen planus worse.
- Avoid scratching these lesions. This can be helped by covering the lesions with a bandage.
- Avoid getting injured frequently because this will trigger new lesions to be formed over the injured area.
If you have the lesions on your mouth, then you also have a higher risk of developing oral cancer and therefore here are some tips that can become helpful to reduce this risk:
- Avoid other things that may increase the risk of developing oral cancer such as smoking, chewing betel, chewing tobacco and consuming alcohol.
- Screen your mouth for oral cancer at least every 6 to 12 months from your dentist or your dermatologist so that oral cancer can be detected early and treatment can be started early.
- Brush your mouth at least two times a day
- Floss your teeth daily.
- Regularly visit your dentist two times a year for a check up and clean your teeth
- Avoid consumption of food that may worsen the lichen planus on your mouth. Some of the foods and beverages that may worsen the lichen planus on your mouth are spicy foods, citrus fruits and juices like oranges and grape fruit,tomatoes, crispy and salty snacks like corn chips, and drinks that may contain caffeine like coffee, tea and coka cola.
If you have lichen planus on your scalp and nails, consult your doctor or your dermatologist if you have been experiencing hair loss as a result of lichen planus. Without receiving the proper treatment, your hair may not grow back therefore consult your dermatologist and get the proper treatment for your hair.
If you have lichen planus lesions on your genetalia, you need treatment, especially if these lesions are red and are open sores. Your dermatologist will provide you treatment that will help to reduce the lichen planus lesions over your vagina, vulva or glans penis.