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

• Lichen Planus Tropicus
• Lichenoid Melanodermatitis
• Summertime Actinic Lichenoid Eruption

What is Actinic Lichen Planus? (Definition/Background Information)

• Actinic Lichen Planus is an uncommon form of lichen planus (LP) that may develop from sun exposure. It causes an eruption of skin lesions on the face and neck (sun-exposed regions of the body). The condition is mainly observed in individuals with darker skin discoloration
• The condition is mostly asymptomatic, and no significant complications are noted. Some cases of Actinic Lichen Planus are known to resolve spontaneously, while others may require treatment using topical steroidal agents and oral medications

Who gets Actinic Lichen Planus? (Age and Sex Distribution)

• Actinic Lichen Planus is a rare skin condition that can affect individuals of all ages 
• Both males and females may be affected
• All racial and ethnic groups may be affected worldwide. The condition is only occasionally noted in Caucasians
• The condition is more common in dark-skinned individuals when compared to fair-skinned individuals

What are the Risk Factors for Actinic Lichen Planus? (Predisposing Factors)

The risk factors for Actinic Lichen Planus may include:

• Exposure to sunlight including ultraviolet (UV) radiation
• Dark-skinned individuals have a generally higher risk for the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s 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 Actinic Lichen Planus? (Etiology)

• Presently, the exact cause of formation of Actinic Lichen Planus is not well-established
• It is described as a photosensitive subtype of lichen planus since the lesions are present on areas exposed to sunlight

What are the Signs and Symptoms of Actinic Lichen Planus?

The signs and symptoms of Actinic Lichen Planus may vary in type and severity among the affected individuals. It may include:

• Presence of lesions on the sun-exposed skin areas
• The skin lesions may be in the form of plaques and papules; they appear as round scaly patches
• These may be encircled by a halo of lighter pigmentation than surrounding skin
• Mild itching may be present at the site of the lesions; but in many, no itching is observed
• The commonly affected areas include the face, neck, and arms/hands
• The involvement of mucosal surfaces is not noted

How is Actinic Lichen Planus Diagnosed?

Actinic Lichen Planus is diagnosed on the basis of the following information:

• A thorough physical examination and a complete medical history are very crucial; a dermatologist will carefully examine the lesions to help in the diagnosis
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Potassium hydroxide (KOH) test: The KOH prep involves microscopic observation of skin scrapings for structures belonging to fungi
• Skin biopsy: A skin tissue biopsy of the lesion is usually performed to confirm the diagnosis. A 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

A differential diagnosis may be necessary to eliminate other conditions that present similar signs and symptoms. This may include:

• Discoid lupus erythematosus
• Granuloma annulare
• Lichen planus pigmentosus
• Lichen planus triggered by other causes, such as medications
• Polymorphous light eruption
• Post-inflammatory hyperpigmentation 
• Sarcoidosis

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 Actinic Lichen Planus?

The complications of Actinic Lichen Planus may include:

• Skin disfigurement causing cosmetic issues
• Emotional stress and low self-esteem

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Actinic Lichen Planus Treated?

The treatment for Actinic Lichen Planus may include topical steroids for the affected skin.

• Administration of oral hydroxychloroquine
• Many other medications and modalities are available to treat Actinic Lichen Planus
• Sun protection using topical sunscreens, wide-brimmed hats, and suitable clothing
• In cases where severe symptoms are present, oral steroid medication for several weeks may be necessary to resolve the condition

How can Actinic Lichen Planus be Prevented?

• The development of Actinic Lichen Planus may be prevented by avoiding exposure to sunlight and/or UV radiation
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Actinic Lichen Planus? (Outcomes/Resolutions)

• The prognosis of Actinic Lichen Planus is usually good for most individuals
• The condition generally resolves either on its own or following treatment with suitable medication

Additional and Relevant Useful Information for Actinic Lichen Planus:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/