Are You Confident of the Diagnosis?

What you should be alert for in the history

The skin eruption associated with frictional lichenoid dermatitis (FLD) is usually asymptomatic or occasionally pruritic. It occurs most commonly in children. Most cases occur in the spring and summer months. Many cases have been associated with outdoor activities and minor frictional trauma from contact with abrasive or irritant materials such as sand, grass, wool, rough materials, and rugs. Many affected individuals have atopic dermatitis, or a personal or family history of atopy.

Characteristic findings on physical examination

On physical examination, the lesions are usually small flat-topped lichenoid papules, commonly seen in areas subjected to trauma and friction—the elbows, knees, and dorsum of the hands (Figure 1). Lesions are less commonly found on the cheeks, neck, chest, back, and buttocks. Individual lesions are 1-3mm in diameter, flesh colored, erythematous or pale, and may aggregate to form plaques. Mild scale and excoriations may be present. Resolution may be associated with hypopigmentation.

Expected results of diagnostic studies

A biopsy is not needed for diagnosis and is rarely reported. Histological examinations of biopsy specimens reveal hyperkeratosis, acanthosis, and lymphocytic infiltration in the superficial dermis. These changes are not specific or diagnostic.

Diagnosis confirmation

The differential diagnosis of FLD includes atopic dermatitis, psoriasis, keratosis pilaris, papular acrodermatitis of childhood, dermatomyositis, flat warts, molluscum contagiosum, and lichen simplex chronicus.

ATOPIC DERMATITIS (AD)

Papular or follicular eczema may appear similar to FLD. FLD may also overlap with AD. Unlike FLD, AD is a chronic or chronically relapsing disease. The distributions of lesions on the skin in AD have some age dependency.

PSORIASIS

Psoriatic papules or plaques are usually erythematous. The papules can become confluent into large plaques. Lesions are commonly present on the scalp, elbows, knees, umbilicus, genitalia, and gluteal crease. Skin involvement with psoriasis can be widespread. Lesions usually have prominent silvery scaling. Nail involvement, such as pitting and separation of the nail plate, can also be present.

KERATOSIS PILARIS (KP)

The rough folliculocentric keratotic papules of KP are typically found on the extensor surfaces of the arms and legs and also commonly seen on the cheeks. It may improve with age.

PAPULAR ACRODERMATITIS OF CHILDHOOD (OR GIANOTTI-CROSTI SYNDROME)

The papules in this condition can be rose to red-brown in color, large, and usually diffusely involve the face, extensor surfaces of the extremities, and the buttocks. This entity can be associated with lymphadenopathy and viral illness.

DERMATOMYOSITIS

The cutaneous findings in this disease include Gottron’s papules-—erythematous or violaceous papules over metacarpophalangeal joints, proximal interphalangeal joints and distal interphalangeal joints. Concurrently erythematous or violaceous papules or plaques located on elbows and knees can be present. This disease is readily distinguished by other features such as the discoloration of the eyelids (heliotrope rash) and proximal muscle weakness.

FLAT WARTS

These papules may be smooth or hyperkeratotic. Numbers of papules can range from a few to hundreds. The papules are commonly present on the face, hands, and shins. Flat warts can be located anywhere on the body.

MOLLUSCUM CONTAGIOSUM

These characteristic papules usually have central umbilication. Papules are sometimes larger than in FLD. In children, papules are commonly present on the face, trunk, and extremities. In adults, lesions are present on the groin and genitalia. Widespread skin involvement is not uncommon, especially in children.

LICHEN SIMPLEX CHRONICUS (LSC)

The solitary or multiple plaques of LSC occur secondary to chronic scratching or rubbing. Lesions can be located on the scalp, nape of neck, and extremities.

Who is at Risk for Developing this Disease?

FLD affects boys more than girls (ratio, 3:1). The age of onset is from 4 to 12 years of age.

What is the Cause of the Disease?

The etiology is unknown. It tends to occur in children with a predisposition for atopy. Some cases have been attributed to skin abrasion from surfaces such as sand and rough carpets.

Systemic Implications and Complications

There are no systemic implications related to FLD.

Treatment Options

FLD can resolve spontaneously after weeks to months. It is generally responsive to low- to mid-potency topical corticosteroids. The use of emollients and keratolytic agents such as lactic acid or urea may also be helpful.

Optimal Therapeutic Approach for this Disease

FLD is a benign and self-limiting disease that can spontaneously resolve after weeks to months. The treatment options include no treatment and treatment with a low- to mid-potency topical corticosteroid (alone or in combination with a keratolytic agent).

If the patient is asymptomatic, no treatment can be an acceptable treatment option. When treatment is desired, triamcinolone 0.1% applied twice a day for 2-3 weeks can be prescribed as first-line therapy. Alternatively, 6-12% lactic acid once daily alone, or in combination with triamcinolone 0.1% cream or ointment once or twice daily can also be utilized.

Patient Management

Parents should be informed that FLD is a benign, self-limiting, often recurrent disease. Lesions may resolve spontaneously in the fall and winter months. Hypopigmentation may be noted on resolution. Children with FLD should be instructed to avoid contact with rough or abrasive surfaces.

Unusual Clinical Scenarios to Consider in Patient Management

Should lesions persist beyond the expected time of resolution, a biopsy should be considered to rule out the entities mentioned in the differential diagnosis, as well as sarcoidosis.

What is the Evidence?

Waisman, M, Sutton, RL. “Frictional lichenoid eruption in children”. Arch Dermatol. vol. 94. 1966. pp. 592-3. (This is an excellent article that describes FLD—its clinical features, etiology, treatment, and differential diagnosis.)

Menni, S, Piccinno, R, Baietta, S, Pigatto, P. “Sutton’s summer prurigo: a morphologic variant of atopic dermatitis”. Pediatr Dermatol. vol. 4. 1987. pp. 205-8. (This article provides a detailed description of the clinical findings of six case reports of children with FLD to determine the true pathogenesis of FLD. All of the cases had either a personal or a family history of atopy. These findings illustrate that an individual’s atopic tendency may be important in the development of FLD.)

Patrizi, A, Di Lernia, V, Ricci, G, Masi, M. “Atopic background of a recurrent papular eruption of childhood (frictional lichenoid eruption)”. Pediatr Dermatol. vol. 7. 1990. pp. 111-5. (This article highlights a retrospective study that evaluates the atopic frequency in 35 children with FLD; 60% of the cases had either a personal or a family history of atopy, suggesting that atopy may trigger FLD.)

Serna, MJ, España, A, Idoate, MA, Quintanilla, E. “Lichenoid papular eruption in a child. Frictional lichenoid dermatitis of childhood (FLDC)”. Arch Dermatol. vol. 130. 1994. pp. 106-7. (This article highlights a case report of a 32-month-old boy with FLD. It highlights the clinical features, etiology, histopathological findings on skin biopsy, treatment, and differential diagnosis.)

Paller, AS, Mancini, AJ. “Clinical pediatric dermatology”. Philadelphia: WB Saunders. 2005. (This book provides a summary of FLD, including the clinical features, etiology, treatment, and differential diagnosis.)

Braun-Flaco, O, Plewig, G, Wolff, HH, Burgdorf, WHC. “Dermatology”. Springer. 2000. (This book provides a summary of FLD, including the clinical features, etiology, treatment, and differential diagnosis.)

Tilly, JJ, Drolet, BA, Esterly, NB. “Lichenoid eruptions in children”. J Am Acad Dermatol. vol. 51. 2004. pp. 606-24. (This article provides a comprehensive review of lichenoid eruptions in children and a succinct summary of FLD, including the clinical features, etiology, treatment, and differential diagnosis.)

Harper, J, Oranje, A, Prose, N. “Textbook of pediatric dermatology”. Oxford: Blackwell Science. 2006. (This textbook provides a summary of FLD, including the clinical features, etiology, treatment, and differential diagnosis.)

Burns, T, Breathnach, S, Cox, N, Griffiths, C. “Rook’s textbook of dermatology”. Oxford: Blackwell Science. 2004. (This book provides a summary of FLD, including the clinical features, etiology, treatment, and differential diagnosis.)