Lichenoid keratosis is an uncommon skin condition marked by formation of benign small lesion along with damaged or abnormal tissue. It is generally a single, tiny, thin darkened plaque or inflamed macule. Patients may also suffer from several eruptive macules of lichenoid keratosis in skin area with sun exposure. The lesion may be reddish brown in the initial stages and over a recovery period of many weeks or months, it will slowly attain a purplish, brownish, or grey hue.
Lichenoid keratosis skin lesion is occasionally called a papule. It typically affects females, older adults, and individuals with light skin. It is usually treated with medications and minor surgery.
Symptoms of lichenoid keratosis
- Lichenoid keratosis does not cause many signs and symptoms. The most common symptom is an abnormal lesion enclosed by an inflamed skin area.
- Patients may develop a single lesion in most cases. Sometimes, a few or many lesions may be noticed.
- The lesion or lesions are tiny and never grow beyond 0.5 to 1 inch.
- The texture of lesions is variable; it can be scaly or quite smooth
- The lesions will generally be reddish or pink in the beginning, but may later turn brownish, grayish, or violet
- Lichenoid keratosis typically appears on skin areas that are continuously or frequently exposed to sunlight (such as trunk or arms, etc.). In some patients, the lesions may form on the head, neck, or face.
- There may be minor itchiness or stinging in some cases.
Types of lichenoid keratosis
The solitary (or sometimes multiple) non-malignant lichenoid keratosis skin lesion typically occurs on the distal upper extremities and the upper trunk area. It may occasionally develop in the neck or head.
Depending on the appearance of the skin lesion, lichenoid keratosis is classified into the below listed subtypes:
- Interface or early subtype: The lesions are brown hyper-pigmented or reddish plaques or papules.
- The bullous, classic, or atypical subtype: In this the lesions develop rapidly, in about three months, and appear as pinkish or red papules or plaques
- Atrophic or late regressed subtype: The lesion may be composed of violet papules or grey/brown skin defects that are often distributed in a random or asymmetrical fashion.
All the above subtypes of lichenoid keratosis can be differentiated under dermoscopy. The skin condition may cause lesions as its only symptom, but some patients may suffer from stinging or prickly sensations or mild itchiness. The lesion surface or texture may be smooth, warty, or scaly. It may be real tiny in size or can grow to more than 1 cm.
Causes
- Lichenoid keratosis develops due to accumulation of excessive amounts of dead keratin cells.
- Keratin is a type of protein that occurs in different body areas, including the hair, nails, skin, and even tooth enamel. Keratin is pushed out by the body onto the skin surface where it dies.
- Buildup of dead keratin cells can result in hard or scaly lesions which may look like lichen. Lichen is a form of scabby fungus that typically grows on rocks and trees. This may be the cause of scaly appearance of lichenoid keratosis in some cases.
- Keratin cells on skin surface are important as they help protect the live cells located just below the layer of dead keratin cells. However, they can cause health problems if the dead keratin cells begin to build up on skin surface. Lichenoid keratosis usually forms if the rate of accumulation of the dead keratin cells is abnormally fast.
- Some experts believe that certain lesions-causing skin disorders like lentigo or seborrheic keratosis regress may increase the risk to development of lichenoid keratosis
- Studies have shown that overexposure or unprotected exposure of skin to sunlight can also increase the risk of lichenoid keratosis formation. In most cases, the skin condition develops over a period of three months.
- Fair-skinned inbdivdiuals in the age group of 30 to 80 years are more prone to developing lichenoid keratosis.
- Females are twice more likely to develop the lesions than males
- The skin condition typically affects Caucasians; it is rare in African Americans, Asians, or Hispanics
Treatment of lichenoid keratosis
A few common methods to treat lichenoid keratosis are listed below:
- Application of prescription topical creams on the lesions. Corticosteroids are the main component of such creams.
- Surgical removal of lichenoid keratosis via use of liquid nitrogen and curettage. In this method, doctors will freeze the lesion with liquid nitrogen. Then a curette is used to scrape off the lichenoid keratosis lesion. There may be minor scarring of skin.
- Other surgical procedures for removal of lichenoid keratosis are electro-surgery or laser therapy.
- Patients may also apply castor oil or aloe vera gel on the lesions. This home remedy is beneficial and effective; however, the healing process tends to be longer as compared to medical treatment.
