Derm Dx: Hair loss and absent follicles

Scalp biopsy revealed absence of hair follicles without inflammation. This finding, along with the history and clinical appearance, led to a diagnosis of pseudopelade of Brocq (PPB).The condition represents a subset of cicatricial alopecia, that is, permanent hair loss resulting...

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Scalp biopsy revealed absence of hair follicles without inflammation. This finding, along with the history and clinical appearance, led to a diagnosis of pseudopelade of Brocq (PPB).

The condition represents a subset of cicatricial alopecia, that is, permanent hair loss resulting from loss or destruction of hair follicles.¹ Cicatricial alopecias are categorized as either primary or secondary, depending on whether the pathologic process is a direct (primary) or indirect (secondary) insult to the hair follicle.² Although data are lacking, it is postulated that primary cicatricial alopecia is responsible for approximately 3% of cases of hair loss, with PPB as a common variant.³ PPB most commonly presents in women between the ages of 30 and 50.²

Pseudopelade of Brocq was named and described by Louis-Anne-Jean Brocq in the late 19th century.⁴ PPB is characterized by well-defined areas of hair loss in an asymmetric pattern.⁵ Histology reveals loss of folliculosebaceous units with minor or absent evidence of perifollicular lymphocytic infiltrate.^2,5 Concomitant loss of facial hair has been reported.⁶ Some patients may experience mild pruritus, although most are asymptomatic.⁷

 

When considering the differential diagnosis, it is worth noting that PPB may resemble lichen planopilaris and discoid lupus erythematosus, which has led to confusion over whether PPB is a distinct clinical entity or an end-stage variant of other conditions.⁸ Microarray analysis suggests that distinct genetic pathways differentiate lichen planopilaris from PPB.⁹ Infectious sources of alopecia should also be excluded before making the diagnosis of PPB.¹⁰

Treatment goals for PPB are aimed at halting progression of the disorder, which can be monitored photographically. Topical and injected corticosteroids may prevent extension of active lesions. Hydroxychloroquine is first-line therapy should systemic medication be required.⁵

Anthony Rainey, BS, is a student at the Commonwealth Medical College in Scranton, Pennsylvania, and Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.

References

1. Sperling LC, Cowper SE. The histopathology of primary cicatricial alopecia. Semin Cutan Med Surg. 2006;25(1):41-50. 
2. Sellheyer K, Bergfeld WF. Histopathologic evaluation of alopecias. Am J Dermatopathol. 2006;28(3):236-259.
3. Dogra S, Sarangal R. What’s new in cicatricial alopecia? Indian J Dermatol Venereol Leprol. 2013;79(5):576-590.
4. Brocq L. Les folliculites et perifolliculites decalvantes. Bull Mem Soc Med Hop Paris. 1888;5:399-408.
5. Alzolibani AA, Kang H, Otberg N, Shapiro J. Pseudopelade of Brocq. Dermato Ther. 2008;21(4):257-263.
6. Madani S, Trotter MJ, Shapiro J. Pseudopelade of Brocq in beard area. J Am Acad Dermatol. 2000;42(5):895-896.
7. Ross EK, Tan E, Shapiro J. Update on primary cicatricial alopecias. J Am Acad Dermatol. 2005;53(1):1-37.
8. Silvers DN, Katz BE, Young AW. Pseudopelade of Brocq is lichen planopilaris: report of four cases that support this nosology. Cutis. 1993;51(2):99-105.
9. Yu M, Bell RH, Ross EK, et al. Lichen planopilaris and pseudopelade of Brocq involve distinct disease associated gene expression patterns by microarray. J Dermatol Sci. 2010;57(1):27-36.
10. Whiting DA. Cicatricial alopecia: clinico-pathological findings and treatment. Clin Dermatol. 2001;19(2):211-225.