Lichen Spinulosus

Lichen spinulosus presents as discrete round plaques that are made up of numerous tiny, monomorphic keratotic skin-colored to slightly hypopigmented papules (Fig. 8.17).
Individual lesions have a keratotic spine protruding from their surface, which results in a rough texture on palpation.
Most often located on the neck, buttocks, abdomen, or the extremities of a child with dry skin or atopic dermatitis.
Plaques may be distributed symmetrically.
May be asymptomatic or mildly itchy.

Differential Diagnosis

Keratosis Pilaris (see Chapter 4: Eczema in Infants and Children)

Common condition seen in children with an atopic predisposition.
Keratotic perifollicular papules typically distributed on the cheeks, lateral arms, and thighs of children and adolescents.

Frictional Lichenoid Dermatitis (see below)

Grouped, monomorphic skin-colored papules usually symmetrically distributed on the extensor elbows and dorsal hands.

Management

Lichen spinulosus may persist unchanged for years or come and go; however there is a tendency for lesions to spontaneously disappear at puberty.
The treatment is similar to what is used for keratosis pilaris and involves keratolytics and emollients.
Lotions or creams containing salicylic acid, glycolic acid, or ammonium lactate such as AM Lactin (12% ammonium lactate) or Cerave SA (6% salicylic acid) may help improve appearance and alleviate symptoms.
Topical vitamin A has been used in resistant and extensive cases.
Most patients are asymptomatic and require no therapy.
Lichen spinulosus runs a variable course. There is a tendency for lesions to spontaneously disappear at puberty.

Points to Remember

Lichen spinulosus is a condition of follicular hyperkeratosis and is regarded as a variant of keratosis pilaris by some.
Lichen spinulosus often goes unnoticed by the patient or family.