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Pseudopelade of brocq introduction
Diseases that cause irreversible hair loss encompass a wide spectrum
of entities characterized by permanent destruction of the hair follicle.
The search for the unknown causes of these disorders has spawned
great intrigue and interest in medical research. The progress made
through case studies and years of investigations has lead to various
conclusions, providing persons in the medical arena a diagnostic
framework when dealing with scarring alopecia.
These hair loss disorders are classified as primary or secondary
alopecias, and primary alopecias are further classified into different
diagnoses based on observation of the hair los patterns and the
results obtained from scalp biopsies. One of the distinctive forms
of primary cicatricial alopecia is pseudopelade of Brocq.
In 1888, Brocq first used the term pseudopelade to describe an
ominous form of scarring alopecia that clinically resembled alopecia
areata. After a comprehensive study of the disorder, in 1905, Brocq,
Lenglet and Ayrignac concluded that pseudopelade is a unique classifiable
entity, a concept that was opposed by many at the time. Even now
the controversy continues, with some researchers maintaining that
pseudopelade of Brocq is very distinct clinico-pathologically, while
others perceive it as a variant of certain other primary alopecias
or the end stage of other conditions. The term pseudopelade has
been used in different ways by different authors. In recent years,
the word “pseudopelade” has evolved to encompass both
the condition as described by Brocq as well as other patterns of
scarring alopecia. The make a clear distinction, when describing
the form of scarring alopecia discovered by Brocq, the diagnosis
is often written as “pseudopelade of Brocq”. So pesudopelade
and pseudopelade of Brocq are not necessarily the same diagnosis!
Despite limitations on research arising out of a fundamental dearth
of case studies and documentation, new discoveries and conceptual
progress help to expand our perception and understanding of this
complex subset of scarring alopecia.
Pseudopelade of Brocq is manifested as small, discrete, smooth,
flesh colored or white alopecic macules or patches without follicular
hyperkeratosis (hardening) or perifollicular inflammation. Over
time, these plaques coalesce into larger patches. This kind of manifestation
of skin plaques has been likened to “footprints in the snow” on
the scalp. Atrophy or degeneration of the hair follicles rather
than scarring has been observed to be its primary feature. Although
some cases have been reported in children, the condition is primarily
seen in adult women.
It is not understood how or why pseudopelade of Brocq occurs, although
some dermatologists suspect it is another autoimmune-based hair
loss. The pathogenesis could be a destructive inflammatory process
involving the upper outer root hair sheath including the area of
the bulge which houses the follicular stem cells.
Pseudopelade of brocq clinical
features
Attempts to clearly explain pseudopelade of Brocq clinicopathologically
have been unsuccessful, and the true epidemiology of pseudopelade
of Brocq remains an unsolved mystery. Brocq originally claimed that
the male sex is more prone to the condition, and onset occurs during
adulthood. Other studies report that women are susceptible to the
condition. There are rare reports of familial disease presenting
during childhood or adolescence.
This form of alopecia is a chronic and insidious condition with
an absence of symptoms other than those affecting the hair follicles.
Because of its enigmatic nature and the lack of information available
to the lay person, early stage lesions are often ignored and only
late stage lesions are brought to the notice of the dermatologists.
The patient with late stage lesions would typically exhibit a well
defined area of hair loss with the absence of most follicular orifices
on the surface of the affected scalp areas. After years of bearing
the disease, most patients have static or burnt out lesions without
scale or redness.
Mild pruritis or itching and diminished lesional sensation may
be present in the individual with an earlier, active stage of the
disease. Brocq described three patterns of pseudopelade: scattered ‘petite
plaques’, large plaques and a combination of these. According
to Brocq and other followers of the theory, atrophic, irregular
shaped, white to ivory plaques with no signs of inflammation are
typically found. Lesional skin is often slightly depressed and supple.
In rare cases, fine, scant scale is present.
Clinical lesions vary in their mode of manifestation. Initial lesions
usually appear as round to oval plaques that measure up to a few
mm in diameter. In patients with fair skin, the lesions are normally
ivory or pearly white in color and occasional reports of diffused
or pale rose coloration has been documented. In East Indian populations,
lesions have been reported as hypo-pigmented, but can also appear
bronze or flesh colored.
Advancement of the condition results in the manifestation of a
number of discrete small plaques in a confetti like distribution
over the scalp. The lesions ultimately coalesce into a large plaque
with irregular borders that may be as large as several centimeters
wide, surrounded by several satellite plaques. Acute lesions may
even be inflammatory. Erythema or redness of the skin or mucous
membrane is mild and in some cases, there may be a slight scale.
Isolated and grouped hairs may be curly or kinky.
Noticable hair loss is not evident for many years as the course
of the disease is slowly progressive, with alternating periods of
inactivity and disease progression. Rapid progression of pseudopelade
of Brocq is very rare. Active disease is marked by a positive pull
test result for anagen hairs at the edge of the alopecia plaques.
The hair pull test is, in essence, very simple. A dermatologist
takes a few strands between their thumb and forefinger and pulls
on them gently. Anagen or growing hairs should remain rooted in
place while hairs in telogen (when the follicle is in a so-called
resting state) phase should come out easily. By determining how
many hairs were pulled and the number that came out, dermatologists
roughly work out the percentage of hair follicles in a telogen state.
This finding is rarely indicative in other forms of alopecia except
in the case of active lichen planopilaris and occasionally in chronic
cutaneous lupus erythematosus.
Pseudopelade of brocq differential diagnosis
It can be difficult to distinguish pseudopelade of Brocq from alopecia
areata, lichen planopilaris, and discoid lupus erythematosus, due
to an overlap of clinical features. This condition also shares features
with central centrifugal cicatricial alopecia (CCCA), an overtly
non-inflammatory scalp condition seen in black women, but it can
be distinguished from the latter with close examination. Pseudopelade
of Brocq normally presents as unevenly bordered, typically atrophic
plaques with irregularly shaped, widely distributed clusters of
hair patches as against a symmetric patch seen in central centrifugal
cicatricial alopecia. In addition, central centrifugal cicatricial
alopecia shows a slow but steady disease progression, whereas the
progression in the case of Pseudopelade takes place in spurts. The
lesions of Pseudopelade are often geometrically shaped, as opposed
to the patches in alopecia areata.
Analysis of tissue biopsies of end stage lesions show that all
follicular structures including sebaceous epithelium are destroyed
to be replaced by collapsed and aggregated follicular adventitia.
These changes are not diagnostic of pseudopelade and can be found
in end-stage lichen planopilaris as well. The Verhoeff-van Gieson
(VVG) elastin stain can help in differentiating pseudopelade from
other forms of alopecia which present common pathologic characteristics,
but display distinct patterns of tissue staining.
Pseudopelade of brocq pathology
Apart from the conclusions drawn by Pierard-Franchimont and Pierard
who noted massive follicular sheath apoptosis in early stages of
the disease, no distinctive details on pathological features of
the tissue destruction process involved in pseudopelade of Brocq
have been ascertained. Routine histological examinations of classic
pseudopelade of Brocq display very non-specific findings. A variably
dense perifollicular lymphocytic infiltrate appears in early stages
of the disease. This is followed by atrophy of the follicular infundibular
(the infundibulum is the segment that extends from the entrance
of the sebaceous gland duct to the follicular orifice of the follicles)
epithelium, concentric lamellar fibroplasia, sebaceous gland loss,
and eventually complete destruction of the sebaceous unit.
A skin biopsy can help significantly in the diagnosis of pseudopelade
even though there are no absolute histological diagnostic markers.
Scalp biopsies should be selected from a hair-bearing region of
the scalp at the edge of an affected area, as biopsies of areas
already devoid of follicles would lead to an incomplete diagnosis.
When a typical lesion of pseudopelade is examined, the expected
findings are the same as those of a burnt out scarring alopecia.
Biopsy of the alopecic, non-inflammatory patches indicated intact
dermal elastic fibers with aggregated elastin adjacent to the fibrous
tracts. End-stage of the disease is characterized by follicular
longitudinal fibrous tracts that extend into the sub-cutis. Elastin
stains reveal dense elastic tissue cuffing a broad, fibrotic tract.
In idiopathic pseudopelade, eosinophilic contraction of dermal collagen
is classically associated with recoil of elastic fibers, culminating
in an appearance of thick, hypertrophic elastic fibers in elastic
tissue stained sections.
Pseudopelade of brocq treatment
As the cause and pathogenesis of Pseudopelade is largely unknown,
diagnostic certainty is most often rather elusive. Monitoring therapeutic
efficiency in such a condition, which is largely asymptomatic and
has no obvious signs of inflammation, presents problems in defining
a specific course of treatment and ascertaining therapeutic efficacy.
Markedly active disease is identified by a positive pull test result
or by observation of extensive hair loss and in principle it should
be treated immediately. However, because of the ambiguous nature
of the alopecia, there is no widely accepted therapy defined as
an effective treatment. Varying degrees of success have been claimed
with use of topical corticosteroids, intralesional triamcinolone
acetonide, prednisone, hydroxy-chloroquine and isotretinoin in the
treatment of pseudopelade of Brocq. Treatment of active lesions
is not any easy proposition, and only when pull tests remain negative
for a minimum period of six months, can drug treatment be withdrawn.
In conclusion, on the one hand, most authors consider pseudopelade
of Brocq as an intractable condition. Other authors advocate the
abolition of
the term altogether, perceiving pseudopelade as the end stage or
clinical variant of other forms of scarring alopecia.
Pseudopelade of brocq references
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of Brocq in beard area. J Am Acad Dermatol. 2000 May;42(5 Pt 2):895-6.
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clinicopathologic study of scarring alopecia due to lichen planus:
comparison with scarring alopecia in discoid lupus erythematosus
and pseudopelade. Am J Dermatopathol. 1999 Aug;21(4):324-31.
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Arch Dermatol. 1987 Feb;123(2):234-7.
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