Lichenoid keratosis is a skin condition that typically occurs as a single, small, raised plaque, thickened area, or papule. It’s also referred to as:
- benign lichenoid keratosis
- lichen planus-like keratosis
- solitary lichen planus
It may be present for three months to more than a year.
This condition is harmless. However, in some cases lichenoid keratosis can be mistaken for other kinds of skin conditions, including skin cancers. If you notice any changes in your skin, you should always ask your doctor to have a look.
Lichenoid keratosis is most commonly found on the:
- upper back
- upper arms
It sometimes occurs on the head, face, and neck. It typically affects skin that’s been exposed to frequent ultraviolet (UV) light from the sun or tanning beds.
Lichenoid keratosis doesn’t normally have any symptoms. In some cases, it may cause:
- skin tightness
- tenderness or discomfort
Lichenoid keratosis typically looks like a small rounded or oval area on the surface of the skin. It can range in size from 3 millimeters to a centimeter or more.
It may look like a sore or wart-like growth. It may appear to be inflamed or red, or like a scaly, dry patch on the skin.
Almost 90 percent of people with lichenoid keratosis will have just one lesion or spot on the skin. In some cases, you may notice a cluster of two to three spots in one or more areas. The spots may be light pink or red in color and can change to a bright purple, gray, or deep brown shade.
If you touch the area it may feel dry, rough, smooth, raised, or thicker in comparison to other areas of skin.
The exact cause of lichenoid keratosis isn’t known. It may be due to an inflammatory reaction. This happens when your immune system mistakenly attacks the skin. This reaction may be triggered by excess sun or UV light exposure, skin irritation, and some medications.
Lichenoid keratosis may also be caused by existing pigmented “sun spots” called solar lentigos, and by another harmless skin growth called seborrheic keratosis. Research shows that almost of people with lichenoid keratosis have the same genetic mutations that are involved in lentigo and seborrheic keratosis.
Lichenoid keratosis is more common in women but also occurs in men. It’s most common in Caucasian women in their 50s and 60s. However, it’s been seen in people 30 to 80 years of age.
Risk factors include:
- middle age or older
- fair skin
- European ancestry
- light-colored eyes
- blonde or red hair
- a history of tanning in the sun or using tanning beds
A dermatologist may be able to diagnose lichenoid keratosis by appearance in some cases. They may also look at the area with a special skin microscope. This is called dermoscopy.
Dermoscopy uses a high-powered microscope to help diagnose lichenoid keratosis and other skin conditions. This medical tool is noninvasive. This means that an expert can look directly at the area and see beneath the skin. There’s no need to cut or remove the spot.
Dermoscopy allows dermatologists and other trained experts to view full-color cells and blood vessels in and under the lesion.
Your doctor may apply mineral oil or a fluid to your skin to help view and take photos of the area with dermoscopy. This procedure is simple and painless.
If there’s any uncertainty, you may still require a biopsy after dermoscopy.
You may require a skin biopsy. This involves numbing the area and removing all or part of the lesion by scraping or cutting. The biopsy sample will be examined by an expert in a laboratory. The lab report will help your doctor confirm the diagnosis and rule out other conditions.
Dermoscopy and a biopsy by trained experts can help verify the difference. For example, under a powerful microscope, a lichenoid keratosis may show gray dots. Skin cancer lesions such as melanoma typically don’t have pigment cells.
Incorrect diagnosis can also happen because the color and texture of lichenoid keratosis changes over time. In the early stages, it may have a reddish-brown color. Later, the lesion may appear grayish-purple or brown, and then become a normal skin shade as it resolves.
You may need several specialist visits and more than one biopsy to confirm the diagnosis between lichenoid keratosis and a lookalike harmful skin condition.
Lichenoid keratosis usually goes away on its own without the need for treatment. Your dermatologist may prescribe treatment for itching, stinging, and other symptoms with:
- topical steroid cream (triamcinolone acetonide 0.1%)
- retinoids (acitretin or etretinate)
- silicone gel
may be used to protect the lichenoid keratosis site from irritating clothing friction. This gel creates a protective barrier to help keep the area moisturized and reduce itching.
The area of lichenoid keratosis may also be removed after numbing the area. Your dermatologist may perform this minor procedure with:
- cryosurgery, freezing with liquid nitrogen
- electrosurgery, removing with an electric current
- curettage, scraping with a surgical instrument
Lichenoid keratosis is harmless and usually clears up on its own. This skin condition isn’t known to cause any type of skin cancer.
See your doctor for any follow-up appointments. Skin changes can be recorded and monitored with dermoscopy photos.
If you’ve had a biopsy or a lichenoid keratosis removed, you may temporarily experience skin itching, tightening, or redness at the area. The site may also become lighter in color.
Lichenoid keratosis can recur even after treatment or removal. You may also get it in a new area. Check your skin regularly and report any changes to your doctor immediately.
Avoid direct sun whenever possible. Take precautions to protect your skin year-round no matter what climate you’re in. Damaging UV rays from the sun and tanning beds are a factor in lichenoid keratosis, as well as in harmful skin conditions. Your dermatologist can recommend the most suitable sun protection for you.