[Lichen planus in children: 12 cases]

Lichen planus is in children uncommon and poorly understood. The classical description is comparable to lichen planus in adults. We conducted a retrospective analysis of 12 cases in children.

Twelve children with lichen planus consulted the Saint-Louis or Robert-Debré hospitals between February 1994 and March 1996. Data collected included: age, sex, ethnic origin, drug use, anti-hepatitis vaccination status, disease history, physical examination, skin histology, liver tests, hepatitis B and C serology, treatment and outcome. Histological proof was obtained in all cases but one (a child with isolated ungueal involvement whose sister had histologically proven ungueal lichen planus).

The clinical features classically described in adults were atypical in all our childhood cases. A rapidly extensive eruption was the main sign in 6 cases. The localizations were unusual with lesions involving all four limbs and the trunk as well as the face in 5 cases and the scalp in 1. Mucosal involvement, observed in 65 p. 100 of adult cases was only found in one of our children. Unguel involvement also appears to be uncommon in children. The etiological pattern was also unusual since we did not observe a single case related to drugs or hepatitis B or C infection. Three children developed a lichen eruption after anti-hepatitis B infection. Four other cases of lichen planus after anti-hepatitis B vaccination have been reported in the literature. Mean delay between the booster vaccination and onset of eruption is reported to be 40 days. The increased incidence of childhood lichen planus in tropical zones suggests ethnic, genetic and climatic factors may be involved. Prognosis is poorly defined in the literature. Certain authors emphasize the long duration of the disease and resistance to treatment in cases of childhood lichen planus. Currently, there is no consensus on treatment. Dermocorticoids in combination with antihistaminics are usually prescribed. General corticosteroid therapy would appear to be warranted in extensive progressive forms with important functional and esthetic impact (scalp involvement with cicatricial alopecia, pigmentation sequellae). The role of other drugs, particularly retinoids, remains to be defined. This retrospective series was not statistically significant. Data in the literature are rather discordant, emphasizing the need for a prospective analysis to acquire a better understanding of the real incidence of childhood lichen planus and better define the therapeutic strategy.