Scarring alopecia in a woman with psoriasis

Diagnosis: Lichen planopilaris

We suspected that this was not simply a case of plaque psoriasis because psoriasis of the scalp only causes non-cicatricial alopecia.¹ Biopsy results confirmed that while the patient did have plaque psoriasis on her scalp, there was also evidence of peri-infundibular fibrosis and inflammation at the junction of the epidermis and dermis along the follicular epithelium. These 2 findings are pathognomonic for lichen planopilaris (LPP).

An uncommon diagnosis

Although its exact incidence and prevalence are unknown, LPP appears to be uncommon.² The condition typically presents in adults ages 25 to 70, and is more common in women than in men.² There is no known association between LPP and psoriasis.

Clinically, LPP manifests as cicatricial hair loss, often in a band-like fashion that can coalesce into larger, reticulated patterns.¹ In addition to the scalp, LPP can affect other hair-bearing areas, such as the eyelids (lashes, brows), body, axillae, or pubic region.^3,4 It is typically accompanied by burning and itching, and commonly presents with perifollicular erythema.¹

Lichen planopilaris is thought to be the result of an immune-mediated lymphocytic inflammatory process.

LPP is thought to be the result of an immune-mediated lymphocytic inflammatory process that produces follicular hyperkeratosis, surrounding erythema, overlying scale, and, eventually, fibrosis and loss of the hair follicle.^3,5

LPP has 3 variants: classic LPP, which typically affects the vertex and parietal areas of the scalp; frontal fibrosing alopecia, which is characterized by frontotemporal hair loss in a band-like pattern (as in our patient’s case); and Graham-Little syndrome, which can include cicatricial alopecia of the scalp and non-cicatricial alopecia of the axillary and pubic areas.³ Postmenopausal women appear to be at heightened risk for frontal fibrosing LPP.⁴