What Is Frictional Lichenoid Eruption?
Frictional lichenoid eruption is a rare, self-limiting skin disease diagnosed with rash in young children. Previously it was believed to have a correlation with atopic dermatitis (a condition where the skin becomes dry, itchy, and inflamed). The rash is typically described as skin-colored or reddish-raised papules on the outer surface of the joints and elbows. The etiology is unknown. The condition is self-limiting. The skin disease was first described by Sutton in 1956 and coined the name “summertime pityriasis of the elbow and knee”.
What Are the Other Synonyms of Frictional Lichenoid Eruption?
The other synonyms of frictional lichenoid eruption are:
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Summertime pityriasis of the elbow and knee.
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Frictional Lichenoid Dermatitis.
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Summertime pityriasis of the elbows.
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Summer lichenoid dermatitis.
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Sutton’s Summer prurigo.
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Papular neurodermatitis.
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Recurrent papular eruption of childhood.
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Dermatosis papulosa juvenilis.
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Dermatosis papulosa adultorum.
What Are the Causative Factors of Frictional Lichenoid Eruption?
The following factors have been implicated in the pathogenesis of frictional lichenoid eruption:
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Friction (minor trauma produced from friction due to contact with abrasives or irritant materials like rugs, sand, grass, wool, and other rough materials).
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Ultraviolet radiations.
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Underlying atopic state (a condition where the immune system becomes more sensitive to common allergies).
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Spring and summer seasons.
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Genetics.
Who Is at Risk for Developing Frictional Lichenoid Eruption?
The boys are more commonly affected than the girls in the ratio of 3:1. The age of onset is usually from four to twelve years.
What Are the Symptoms of Frictional Lichenoid Eruption?
The following clinical features are reportedly seen in the disease:
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Children are more commonly associated with the disease.
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It can affect any age group.
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It most commonly occurs in the spring and summer seasons.
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The most common sites of involvement are the elbows, knees, and dorsal hands. The lesions may be less commonly found on the cheeks, neck, chest, spine, and hips.
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The papules are usually asymptomatic but sometimes pruritic (itchy).
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Morphologically the skin lesions appear as either skin-colored lichenoid papules arranged in clusters or as faintly discolored and hypopigmented, pinhead-sized, raised flat-topped papules on a dark background.
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Crusting of the papules can occur in severe cases.
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Skin rashes tend to resolve spontaneously. Occasionally, topical corticosteroid therapy is required for long-lasting skin lesions.
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The number of lesions may vary from few to many since they coalesce to form plaques. The lesions are typically one to three millimeters in diameter.
What Is the Differential Diagnosis of Frictional Lichenoid Eruption?
The differential diagnosis of frictional lichenoid eruption includes:
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Atopic Dermatitis- Papular eczema (patches of skin becoming rough and inflamed) may appear similar to frictional lichenoid eruption. However, unlike frictional lichenoid eruption, atopic dermatitis is a chronic recurring skin disease.
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Psoriasis- The plaques of psoriasis are usually erythematous. The papules usually coalesce to form large plaques. The psoriatic lesions are more commonly found on the scalp, elbows, knees, umbilicus, and genital organs. In the case of psoriasis, there is widespread skin involvement. A prominent silver scaling is seen in the psoriatic lesions. Nail pitting and nail plate separation can also be present.
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Keratosis Pilaris- The rough keratotic papules are typically present on the extensor surfaces of the upper and lower extremities. They are also commonly seen on the cheeks. The lesions improve with age.
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Dermatomyositis- The skin findings in this disease include reddish or violet papules over metacarpophalangeal joints, proximal interphalangeal joints, and distal interphalangeal joints. These papules or plaques can also be present on elbows and knees. This disease can be distinguished from a frictional lichenoid eruption by other clinical features such as the depigmentation of the eyelids and weakness in the proximal muscles.
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Flat Warts- Usually the lesions are smooth or hyperkeratotic. The number of papules usually ranges from a few to hundreds. The skin lesions are classically present on the face, hands, and front of the legs below the knees.
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Molluscum Contagiosum- Usually small lumps are developed on the skin that is pearly-white or slightly pink. A tiny dimple is usually developed in the center of each molluscum. The molluscum papules are sometimes larger than the frictional lichenoid eruption papules.
How Is the Diagnosis of Frictional Lichenoid Eruption Established?
Diagnosis usually depends on the characteristic clinical presentation of the skin disorder along with the age of the child, the time of the year when it occurs, the type of treatment modality, and relapses over the period of time. The typical rash appears as flesh-colored mildly pigmented papules on the extensor surface of the knees, elbows, and sometimes the dorsal surface of hands. No laboratory or imaging techniques are required. A biopsy is usually not performed. But microscopic examination will reveal epithelial changes like orthokeratosis, and epidermal hyperplasia with lymphocytic infiltration of T cells in the epithelium at some places along with upper dermal fibrosis.
What Is the Treatment and Management of Frictional Lichenoid Eruption?
Usually, the disease rash is self-limiting, but if the parents or child are concerned about the symptoms, mild topical corticosteroids can be prescribed to control these symptoms. Vaseline petroleum jelly is also advised in some cases. It is a clinical skin disorder that is exacerbated by friction. Hence, the patient is advised to wear loose cotton clothes to avoid friction. Since this disease is aggravated by ultraviolet rays, it is advisable for the patient to sun protect himself from the harmful ultraviolet rays. No prophylactic therapy is required and a new flare-up of the rash can appear in the following summer or spring season.
What Is the Best Treatment for Frictional Lichenoid Eruption?
The most commonly prescribed medicine for inflammatory reactions is antihistamines. Antibiotics are most frequently prescribed in case of a superimposing infection. A healthcare professional can also recommend certain steroid gels for topical application. Based on the severity of the rash, the doctor may also suggest steroid injections or phototherapy treatment.
Conclusion
Frictional lichenoid eruption is a benign, self-limiting, and usually recurrent disease. It usually resolves within weeks or months. The diagnosis is usually determined on the basis of clinical presentation. The use of topical corticosteroids, emollients, and keratolytic agents such as lactic acid may be useful to provide symptomatic relief to the patient.
