Lichen sclerosus (Non-genital) 

An uncommon chronic atrophic disease of unknown etiology in which characteristic, easily recognized, small, white, sclerotic areas occur at any site on the skin. It may occur in genital and non-genital skin separately or together.

Incidence

Females outnumbered males by 10: 1. Involvement of the vulva, perineum and perianal skin in females is more common than balanitis xerotica obliterans, which is the corresponding lesion in the adult male. The condition occurs particularly around and after the menopause (peri- or postmenopausal), but also occurs in girls between the ages of approximately 1 and 13 years (prepubertal) and also common in boys.

Clinical features

Non-genital lesions

The lesions on the skin are symptomless and occur on the trunk, particularly on the upper back, around the neck, around the umbilicus, sites of physical trauma or continuous pressure (e.g. the shoulder or hip, underneath bra straps or belts), in the axillae, on the flexor surfaces of the wrists, thighs and buttocks, around the eye and, very rarely, on the scalp, palms and soles. Early lesions are small, smooth, shiny, ivory- white, polygonal, flat-topped, slightly raised papules with an erythematous halo, but occasionally they are semi translucent and resemble mother-of-pearl. Surface of lesions typically shows prominent dilated pilosebaceous orifices, filled with keratin plugs (dells); if plugging is marked, surface appears hyperkeratotic or warty.  Over time, these papules often coalesce to form small oval white plaques which resemble morphoea, but the individual lesions of lichen sclerosus can nearly always still be identified.The flattened interface between the epidermis and dermis results in fragility of the dermal–epidermal junction; as a result, lichen sclerosus is occasionally complicated by the development of bullae that tend to become hemorrhagic because of extravasation of erythrocytes in them.  Occasionally, telangiectases and purpura may occur due to dilatation of venulesand extravasation of erythrocytes respectively. In the later stages, atrophy occurs, and the surface of the lesions becomes wrinkled, and may actually be depressedwith a cellophane paper-like texture to the white plaques classically.

Biopsy reveals:

·       Epidermal atrophy.

·       Vacuolar alteration of dermo-epidermal junction.

·       Sclerosis of the papillary dermis.

Treatment

1.   The first-line treatment for all types is the use of superpotent topical glucocorticoids. Tacrolimus ointment not useful for patients with extragenital lichen sclerosus. Pulsed high-dose corticosteroids combined with low-dose methotrexate treatment in patients with refractory generalized extragenital lichen sclerosus.

2.   Other treatments: Narrowband UV-B phototherapy. Pulsed dye laser. Topical and oral retinoids PUVA. UVA1 phototherapy. Antimalarials.