Brocq Pseudopelade Workup

Updated: Mar 10, 2017
  • Author: Kendall M Egan, MD, FAAD; Chief Editor: William D James, MD  more...
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Laboratory Studies

Other than scalp biopsy, no laboratory test has been found useful in establishing the diagnosis of pseudopelade of Brocq. If the history or physical examination findings suggest evidence of lupus erythematosus, antinuclear antibody testing would be appropriate.



Scalp biopsy

Two 4-mm punch biopsy specimens should be obtained from an orientation along the direction of the hair follicle. Specimens should ideally be taken from a clinically well-established but active area of alopecia to include both normal and affected hair-bearing areas. One punch biopsy specimen should be submitted for horizontal sectioning and one for vertical sections if possible, both stained with hematoxylin and eosin and elastic tissue stains. The second punch biopsy specimen can be bisected vertically to accommodate both direct immunofluorescence (DIF) and hematoxylin and eosin staining. [7]


Histologic Findings

The histopathologic criteria established by Pinkus were not correlated in any way with the clinical features. [17] Thus, pseudopelade as described by Pinkus is a histologic and not a clinical entity. In secondary pseudopelade, the histologic findings are those of a burnt-out scarring alopecia with absent hair follicles and fibrosis. Elastic tissue is absent in scarred areas. Idiopathic pseudopelade is characterized by a contracted dermis with dense collagen and loss of space between collagen bundles. Elastic fibers are recoiled and appear thick. Broad fibrous tract remnants are noted with preservation of the elastic sheath.