Sir,
Lichen planus pigmentosus (LPP) is a rare variant of lichen planus that presents as asymptomatic to mildly pruritic, hyperpigmented macules and/or patches. This dermatosis has been rarely reported in children. We report a first series of childhood LPP illustrating 5 cases from Tunisia.
Of 5 patients (age range 6–16 years), 3 were male (mean age, 9.3 years) and 2 were females (mean age, 13 years). The duration of disease at presentation ranged from 1 month to 1 year. In 4 patients, lesions were present at more than one anatomical site and the patients had bilateral involvement. The trunck was the commonest site affected (4 cases). In our all cases, the lesions were a few mm to a few cm in diameter (
Pigmented brownish, well-defined macules located on the neck.
No elevated active red border as seen in erythema dyschromicum perstans was noticed in any patient. The history of previously inflammatory processes in affected areas was not present. All cases had no concomitant diseases. Related external factors such as drug intake prior to the onset or use of cosmetics were absent. Our second patient reported that lesions appeared after the exposure to a severe stress. None of our patients had a family history of a similar skin disorder.
Of the 4 patients, who were treated with topical betamethasone, two showed a slight lightening of the pigmentation after an average of 16 weeks.
Skin biopsies were performed from all the patients. Three patients had band-like lymphocytic infiltrate and two patients had superficial perivascular pattern. Melanin incontinence was a constant finding in all cases. Hyperkeratosis was marked in three cases and keratinocyte necrosis in one case.
The clinical, histological and therapeutic features of our patients are summarized in
Clinical, histological, and therapeutic features of patients
We reported 5 Tunisian cases of childhood LPP, a rare entity in children. LPP is a rare variant of lichen planus, first described by Bhutani et al [
LPP is characterized by the presence of the hyperpigmented, dark-brown macules in the sun exposed or flexural areas of the body. Face and neck are the most frequent initial sites of involvement. Palms, soles and nails are not affected. Although lesions are generally asymptomatic, mild pruritus and burning sensations are present in about one-third of patients [
Our fourth patient presented oral lesions. In fact, while Bhutani et al [
Histopathological examination typically shows vacuolar alteration of the basal layer, variable dense of lymphocyte infiltration, pigmentary incontinence and melanophages in the superficial dermis. In our cases we have found similar histopathological results, as well.
The differential diagnosis of childhood LPP includes idiopathic eruptive macular pigmentation, ashy dermatosis and post-inflammatory pigmentation.
The etiopathogenesis of the condition remains unknown. Kanwar et al suggested that mustard oil, amla oil, henna and hair dye could be the precipitating factors in predisposed individuals [
The disease is insidious in onset and has a chronic course [
To conclude, LPP in childhood is uncommon. As this was a first series of childhood LPP. It confirms the literature data when the scarcity of the entity and the disappointing response to treatment. Mucosal involvement might be not infrequent. However, additional studies are needed to better characterize this entity in children.