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Scarring alopecias - an overview
Scarring alopecias, also called cicatricial alopecias, are a
group of dissimilar disorders that each result in irreversible
hair loss. This permanent hair loss can stem either from a primary
or secondary process. In this section the primary focus is on
the primary cicatricial alopecias, which involve destruction of
the hair follicle and loss of follicular ostia (ostia are the
openings of the hair follicles through which the hair fibers emerge)
as a result of a specific disease mechanism exclusively focused
on the hair follicles and which does not affect other tissues
and organs of the body. Secondary processes are more generalized
disease mechanisms that can damage several tissues and organs
as well as inducing scarring alopecia.
Primary cicatricial alopecia conditions are usually non-scarring
initially (a fact that makes diagnosis quite challenging) with
the scalp erupting into colored spots and lesions. In due course
of time, the scalp takes on a patchy appearance – irregular
bald patches appearing in the midst of normal to sparse growth
of hair. In its advanced stages, the hairline can recede and the
bald patches grow, ultimately leading to extensive and even total
scalp baldness. New discoveries and research findings are adding
to our knowledge of these disorders.
With regards to the classification systems for primary cicatricial
alopecia, several methods have evolved – some based on the
age of onset, some on clinical features and yet others on pathology.
The most popular opinion on the classification of primary cicatricial
alopecias among dermatologists is that of the North American Hair
Research Society (NAHRS) team comprising eminent hair clinicians,
pathologists, and researchers. Their classification or categorization
is based on the principal inflammatory cell type (“lymphocytic” or “neutrophilic”)
noticed/detected in scalp biopsy specimens taken from clinically
active lesions. Disorders that cannot be correctly classified
under either of these two specific headings are identified as “mixed” or “non-specific”.
Lymphocytic
cicatricial alopecias
According to the NAHRS consensus, the lymphocytic cicatricial
alopecias can be further classified into the following categories:
• Discoid lupus erythematosus or Chronic cutaneous lupus
erythematosus
•
Lichen planopilaris
a) Classic lichen planopilaris
b) Frontal fibrosing alopecia
c) Graham-Little syndrome
•
Classic pseudopelade (of Brocq)
•
Central centrifugal cicatricial alopecia
•
Alopecia Mucinosa
•
Keratosis follicularis spinulosa decalvans
Discoid Lupus Erythematosus (DLE) or Chronic Cutaneous Lupus
Erythematosus
Discoid Lupus Erythematosus (DLE) is the one and only form of
chronic cutaneous lupus erythematosus that results in primary
cicatricial alopecia. The exact cause and pattern of DLE development
has yet to be uncovered; however, a complex interaction of genetic,
environmental and a host of other factors lead to expression to
this disease. Some dermatologists suggest that exposure to ultraviolet
light provokes or incites keratinocyte apoptosis and a reactive
T-cell- or immune-complex-mediated response. Yet, another consideration
in the pathogenesis of scalp DLE is koebnerization – the
development of the disease in areas of skin damaged due to excoriation
and wounds.
Studies prove that more adult women are affected by DLE than
adult men, but this is by no means an indication that children
are spared. Among children, however, the non-scalp version of
the disease is prevalent. Patients suffering from this form of
scarring alopecia complain of hair loss, increased shedding and
pruritus. A stinging or burning sensation with symptoms of scalp
tenderness is commonly experienced. The initial lesion, or erythematous
papule, exhibits a centrifugal spread and takes the shape of a
coin (discoid). In its advanced stage the erythema diminishes
followed by atrophy (the skin breaks down), telangiectases (red
spots on the skin), hypo-pigmentation (reduced skin color) or
de-pigmentation (no skin color) and ultimately the loss of follicular
ostia (hair follicle openings) become apparent. Complications
arising from scalp DLE include significant cosmetic disfigurement,
ulceration and Squamous Cell Carcinoma (SCC is a potentially life
threatening ailment).
Lichen Planopilaris
Lichen planopilaris is considered a follicular (hair follicle
focused) variant of lichen planus (LP) because it follows the
same developmental pattern as classic LP. Three forms of lichen
planopilaris are recognized: classic lichen planopilaris, frontal
fibrosing alopecia and Graham-Little syndrome.
Classic lichen planopilaris: Occurring mainly in adult women,
this cicatricial alopecia exhibits symptoms like skin flaking,
hair loss and pruritus. The spread of the disease or infection
is confined to the hair-bearing rim and unaffected, healthy hairs
are present within the rim. The prime site affected is the central
part of the scalp (the entire scalp is rarely involved). Pain,
a burning or itching sensation and scalp tenderness are often
experienced as the lichen planopilaris develops. Ulceration is
the most common complication arising from classic lichen planopilaris.
The initial stages of the disease often go unnoticed. When the
epidermis is affected, pigmentary incontinence becomes prominent
and lumps of pigment are seen in skin biopsies. Later on, follicular
destruction occurs and foreign-body hair-shaft granulomas become
apparent in the skin biopsies. The final stage is marked by the
appearance of longitudinal tracts of fibrosis at the sites of
former follicles.
Frontal Fibrosing Alopecia: This variant of lichen planopilaris
occurs mostly in postmenopausal women; it is characterized by
the recession of the frontotemporal hairline. This seldom pruritic
scarring alopecia condition also affects the eyebrows and they
are often thinned. The affected part of the scalp is of variable
width – with a shiny band of partial hair loss (ranging
between 1-8 cm) being apparent.
Graham-Little Syndrome: This form of lichen planopilaris affects
adults and manifests itself as patchy cicatricial alopecia of
the scalp, non-scarring alopecia of the axillary (under arm) and
pubic areas and grouped spinous follicular papules (little lumps
in clusters) on the trunk skin and extremities of the arms and
legs.
Pseudopelade of Brocq
Pseudopelade of Brocq is a chronic, sinister form of primary
cicatricial alopecia condition, which is most common among adult
males. Pseudopelade of Brocq hardly produces any symptoms or any
inflammation that is obvious on clinical examination. The NAHRS
group’s definition of pseudopelade of Brocq is – ‘discrete,
smooth, flesh-toned areas of alopecia without follicular hyperkeratosis
or perifollicular inflammation.’
This scarring alopecia follows three different developmental
patterns: scattered petite plaques, large plaques, and a mishmash
of these two morphologies. Initially, the lesions are round to
oval plaques, which are ivory or pearly white in color. As for
the lesion-skin, it is usually slightly depressed and supple.
On rare occasions, scales are also noticed. When the situation
worsens, the lesions coalesce to form a large plaque, with small
plaques scattered round the periphery. The slow pace of the spread
of the disorder is reflected in the slow hair loss experienced
by the patients.
Central Centrifugal Cicatricial Alopecia
Central centrifugal cicatricial alopecia (CCCA) is an overtly
non-inflammatory cicatricial alopecia condition of the central
scalp that spreads centrifugally. The term coined by the NAHRS
group now stands for follicular degeneration syndrome, which is
relatively common among adult black men and women compared to
other ethnicities. The condition is not accompanied by much inflammation
as seen in skin biopsies; however, the vertex of the scalp undergoes
scarring and becomes supple and shiny.
Alopecia Mucinosa
Alopecia Mucinosa is an inflammatory scarring alopecia condition
that affects all people irrespective of age. It is characterized
by intrafollicular mucin deposition. There are distinctly two
types of alopecia mucinosa: primary idiopathic and secondary lymphoma-associated
disease. The primary condition is also considered as a premalignant
condition or a slow-progressing form of follicular mycosis fungoides
(MF).
The cicatricial alopecia condition is typified by the appearance
of scaly lesions, tumors, pores and indurate plaques. Those affected
often go through pruritus (an itching sensation), dysesthesia
(painful sensations) and anhidrosis (an absence of sweating in
the affected skin). The commonly affected parts are the head and
the neck; however, the disease can spread elsewhere in the body.
This alopecia is also marked by partial to complete hair loss.
Keratosis Follicularis Spinulosa Decalvans
A widespread follicular hyperkeratosis, which eventually leads
to atrophy (a wasting away of the skin), photophobia (a reaction
to sunlight) and cicatricial alopecia of the scalp has been termed
Keratosis follicularis spinulosa decalvans. Also known as keratosis
pilaris decalvans, this disorder is an inherited X chromosome-linked
disease.
Making its appearance in early childhood, KFSD first affects
the eyebrows, cheeks, forehead, and nose. Later on, the disease
spreads to the scalp, neck, trunk and extensor extremities. Mild
pruritus and tenderness are experienced at the affected sites.
Scalp, eyebrow, eyelash alopecia and loss of follicular ostia
apart, acute KFSD also leads to the formation of scalp pustules.
Many eye abnormalities are also associated with KFSD.
Neutrophilic
cicatricial alopecias
The NAHRS group has classified Neutrophilic Cicatricial Alopecias
into two sub-groups or categories of diagnosis:
• Folliculitis Decalvans
•
Perifolliculitis Capitis Abscedens Et Suffodiens
Folliculitis Decalvans
Characterized by suppurative folliculitis (inflamed hair follicles
that discharges pus), this scarring alopecia is an outcome of
the patient’s susceptibility to infections due to systemic
or local immune deficits and S aureus strain related properties.
(Both acquired and inherited immune disturbances are associated
with folliculitis decalvans).
This disorder affects adults of both the sexes. Initially appearing
as a follicular pustule or papule, the lesion soon takes the shape
of a miliary abscess (small injuries the size of millet seeds).
Layers develop and in the advanced stage, the atrophic area is
affected by scarring alopecia. The infection or spread of the
disease is usually limited, confined to the periphery and the ‘zone
of folliculitis’ is specifically bordered.
Perifolliculitis Capitis Abscedens Et Suffodiens
The incidence of perifolliculitis capitis abscedens et suffodiens
is higher among men, especially black men, compared to women.
In this type of cicatricial alopecia abnormal follicular keratinization
causes obstruction in the hair follicle, which, together with
secondary bacterial infection, results in follicular destruction
and widespread disease.
The onset of the disease is marked by the formation of a follicular
pustule usually on the occipital or vertex scalp. This soon transforms
into a painful, bulbous, firm or fluctuant nodule (which usually
exudes purulent material). This is followed by the development
of non-scarring alopecia over the nodules, which eventually turns
into cicactricial alopecia.
Mixed
cicatricial alopecias
The NAHRS group have subdivided the non-specific or mixed cicatricial
alopecias into three categories:
• Acne Keloidalis
• Acne Necrotica
• Erosive Pustular Dermatosis
Acne Keloidalis
An inflammatory condition that predominantly targets the nuchal
hairline of young, black postpubertal males, the name acne keloidalis
is very misleading as it is neither similar to an acne condition
nor to the keloid condition. It is a race-related disease and
is stimulated by a variety of reasons like autoimmunity, excoriation,
infection of hair follicles with Demodex, bacteria, etc.
Soft papules appear in the early phases of the disease. Later
on, they become pustular and crusted and cause a burning sensation.
In more advanced stages they band together and form larger nodules
or plaques. This eventually leads to scar formation and transepithelial
elimination of hair.
Acne Necrotica
Acne necrotica, also known as folliculitis necrotica, can be
subdivided into two types: Acne Necrotica varioliformis (varioliformis
means it looks like smallpox) and acne necrotica miliaris. Of
these two, only the former is a scarring alopecia. With the affected
regions breaking into papules or papulopustules, this alopecia
is a distinctive necrotizing disorder of the hair follicle that
heals leaving behind varioliform scars. The disorder is triggered
by hair follicle infections with S. aureus or Propionibacterium
acnes folliculitis, or neurotic excoriation (obsessive scratching)
of an underlying folliculitis. This alopecia condition is quite
painful with significant itching and is often a relapsing disorder.
Erosive Pustular Dermatosis
Erosive pustular dermatosis is a chronic, relapsing amicrobial
pustular dermatosis that affects the scalp and promotes cicatricial
alopecia. The definite causes of this unique dermatiosis are yet
to be specified and various factors like accidental scalping,
minor lacerations, skin grafting, sunburn, etc. are believed to
lead to this scarring alopecia condition.
Predominant among the elderly, the initial condition is characterized
by lesions, which develop into outwardly crusted plaques. Removal
of this upper crusty coat of skin reveals flabby pustules that
exude pus. Cicatricial alopecia, a cardinal feature of this disease,
is an outcome that develops after years of negligence and lack
of treatment. A caution in this regard is that further aggravation
can lead to the development of secondary carcinoma (skin cancer)
with squamous and/or basal cell features.
Scarring
alopecias
references
- Ross EK, Tan E, Shapiro J. Update on primary
cicatricial alopecias. J Am Acad Dermatol. 2005 Jul;53(1):1-40.
PMID: 15965418
- Tan E, Martinka M, Ball N, Shapiro J. Primary
cicatricial alopecias: clinicopathology of 112 cases. J Am Acad
Dermatol. 2004 Jan;50(1):25-32. PMID:
14699361
- Wiedemeyer K, Schill WB, Loser C.
Diseases on hair follicles leading to hair loss part II: scarring
alopecias. Skinmed. 2004 Sep-Oct;3(5):266-271. PMID: 15365263
- Olsen EA, Bergfeld WF, Cotsarelis G, Price VH, Shapiro J,
Sinclair R, Solomon A, Sperling L, Stenn K, Whiting DA, Bernardo
O, Bettencourt M, Bolduc C, Callendar V, Elston D, Hickman J,
Ioffreda M, King L, Linzon C, McMichael A, Miller J, Mulinari
F, Trancik R; Workshop on Cicatricial Alopecia. Summary of North
American Hair Research Society (NAHRS)-sponsored Workshop on
Cicatricial Alopecia, Duke University Medical Center, February
10 and 11, 2001. J Am Acad Dermatol. 2003 Jan;48(1):103-10.
PMID: 12522378
- Headington JT. Cicatricial alopecia.
Dermatol Clin. 1996 Oct;14(4):773-82.
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