What are the other Names for this Condition? (Also known as/Synonyms)

• Benign Lichenoid Keratosis
• Involuting Lichenoid Plaque
• LPLK (Lichen Planus-like Keratosis)

What is Lichen Planus-like Keratosis? (Definition/Background Information)

• Lichen Planus-like Keratosis (LPLK) is a common benign skin tumor. It can resemble other benign and malignant tumors such as basal cell carcinoma, seborrheic keratosis, and actinic keratosis 
• They are generally observed in middle-aged and older adults, especially in those who have a lighter-skin. Lichen Planus-like Keratosis tumors are usually solitary in nature, though sometimes multiple tumors have been observed
• The cause of development of the condition is unknown, though the risk factors for Lichen Planus-like Keratosis include exposure to sun and ultraviolet (UV) light
• These tumors are often present on the trunk and extremities (on sun-exposed areas). Since, these pigmented tumors resemble many malignant tumors, they are frequently biopsied to ensure a definitive diagnosis
• A treatment of Lichen Planus-like Keratosis may be undertaken, if they present cosmetic issues. In such cases, a simple surgical excision is sufficient treatment. The prognosis is excellent on removal of the tumor

Who gets Lichen Planus-like Keratosis? (Age and Sex Distribution)

• Lichen Planus-like Keratosis is commonly seen in adults in the age group of 30-80 years
• It is observed in both men and women; a preference for women is noted
• LPLK is observed worldwide across all racial and ethnic groups; however, lighter-skinned individuals (especially Caucasians) are more prone to Large Cell Acanthomas than darker-skinned individuals (such as Asians, Africans, etc.), in whom it is observed very infrequently

What are the Risk Factors for Lichen Planus-like Keratosis? (Predisposing Factors)

The risk factors for Lichen Planus-like Keratosis include:

• Exposure to sunlight and UV light
• Skin tanning (use of tanning beds)
• Caucasians are more vulnerable compared to other darker-toned individuals

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Lichen Planus-like Keratosis? (Etiology)

• The exact cause and development of Lichen Planus-like Keratosis is presently unknown
• It seems to be influenced by exposure to sunlight (UV light)

What are the Signs and Symptoms of Lichen Planus-like Keratosis?

In most cases, Lichen Planus-like Keratosis does not present any signs and symptoms. However, the following may be noted:

• They generally occur as single lesion (mostly) or multiple skin lesions that are observed on the chest, back, arms, and legs (areas exposed to the sun); the head and neck region is not regularly affected
• It is a slow-growing tumor and are often less than 1 cm in size (1-10 mm)
• By their appearance, LPLK may resemble basal cell carcinoma, seborrheic keratosis, and actinic keratosis
• These lesions can be pigmented and may also be mistaken for melanoma of skin (a malignant tumor of skin)
• Lichen Planus-like Keratosis is associated with slight itching

How is Lichen Planus-like Keratosis Diagnosed?

A diagnosis of Lichen Planus-like Keratosis may involve the following procedures and tests:

• Complete physical examination with evaluation of medical history
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Note: The diagnosis of Lichen Planus-like Keratosis need not involve a biopsy. However, since there is a suspicion of many malignant conditions, the healthcare provider may recommend a biopsy in most cases.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Lichen Planus-like Keratosis?

No significant complications generally arise from Lichen Planus-like Keratosis.

• They may present cosmetic concerns, in which case a surgery may be proposed
• Its resemblance to cancerous tumors may cause psychological stress on the individual

How is Lichen Planus-like Keratosis Treated?

Lichen Planus-like Keratosis may not require any treatment in a majority of cases. However, in case they present cosmetic issues in the individual, they may be removed.

• The healthcare provider may chose to regularly monitor the tumor, if they are asymptomatic. A ‘wait and watch’ approach may be adopted
• A complete surgical excision can result in a cure
• Shave excision is often an appropriate choice
• If the diagnosis is already confirmed by a biopsy, or the practitioner considers the diagnosis clinically firm, cryotherapy is a common option
• Follow-up care with regular screening and check-ups are important

How can Lichen Planus-like Keratosis be Prevented?

• Current medical research has not established a definitive method of preventing the formation of Lichen Planus-like Keratosis
• However, overexposure to sun’s rays and UV light should be avoided

What is the Prognosis of Lichen Planus-like Keratosis? (Outcomes/Resolutions)

• The prognosis of Lichen Planus-like Keratosis is excellent on its complete excision and removal
• Since, these are benign tumors, the prognosis is excellent, even if no treatment is provided and only periodic observation is maintained

Additional and Relevant Useful Information for Lichen Planus-like Keratosis:

• Lichen Planus-like Keratosis is not an infectious condition; they do not spread from one individual to another
• There is no definitive proof that consuming certain foods influence its development