Lichen Planus Pemphigoides

Lichen planus (LP) pemphigoides is a rare cross-over syndrome between lichen planus and bullous pemphigoid (see these terms).

Epidemiology

The prevalence is unknown.

Clinical description

LP pemphigoides affects primarily adult men in middle age (40-50 years of age), but several cases have been reported in children. It is quite distinct from bullous lichen planus (see this term), both clinically and pathologically. In lichen planus pemphigoides, bullous lesions arise in both normal skin and skin affected by lichenoid lesions, whereas in bullous lichen planus, the blisters only develop on lichenoid papules. The bullae in LP pemphigoides can be hemorrhagic or clear, and have a predilection for acral sites.

Etiology

Epitope spreading seems to account for the pathogenesis of lichen planus pemphigoides, whereby damage to the basal layer in LP lesions exposes a basement membrane antigen (e.g. BP180 epitope) leading to the development of circulating antibodies. Occurrence of LP pemphigoides has been reported following the use of several medications including cinnarizine, angiotensin-converting enzyme (ACE) inhibitors (ramipril and captopril), simvastatin and anti-tuberculous drugs, and also following Psoralen and Ultraviolet A Light (PUVA) therapy.