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Secondary
scarring alopecia from developmental and hereditary disorders
Permanent alopecia may also arise from a wide variety of developmental
and hereditary disorders. While some of these disorders are associated
with true cicatricial alopecia (fibrosis), some have been linked
with pseudocicatricial alopecia (hyalinization of collagen and normal
elastin), yet others with dysgenesis (defective development) resulting
in atrophy and a wasting away of the follicular units, or abnormal
keratinization (keratin formation or development of a horny layer;
may also apply to premature formation of keratin).
Fibrodysplasia
Polyostotic (involving more than one bone) fibrous dysplasia (abnormality
of development, in pathology, alteration in size, shape and organization
of adult cells) or Albright's disease (a rare autosomal dominant
disorder) induces a state of permanent alopecia. Other than the
scalp region, the disease affects pubic areas, axillary hair and
even the eyelashes. Microscopic analyses of the biopsy samples confirm
the presence of fibrous ‘coils’ with increased cellularity
(the degree, quality, or condition of cells that are present) and
vascularity (presence of vessels or system of vessels for conveying
blood or lymph) along with haphazard arrangement of fibrocytes (the
inactive form of stellate shaped cells present in connective tissue
capable of forming collagen). Underlying hyperplasia of the panniculus
(a sheet or layer of tissue) and small osteomas (benign tumour of
bone material) in the skin, associated with follicular fibrous tracts,
are also revealed. The connective tissue tracts show improper development
of elastic tissues. Follicular structures, if at all present, display
the clumping of elastic tissues in tight opposition to the follicular
epithelium.
Ectodermal Dysplasias
Ectodermal dysplasias are a complex group of hereditary conditions
(most often X linked) that is characterized by the abnormal development
of skin, absence of sweat glands, dry eyes and abnormal development
of teeth. Symptoms can include absent teeth, cicatricial alopecia,
peg teeth, inability to sweat, thin skin and heat intolerance. Mucous
membrane involvement may result in a foul-smelling nasal discharge.
The inability to sweat leads to the inability to maintain normal
body temperature in a warm environment. Some affected people exhibit
fevers and require artificial cooling.
There are many ectodermal dysplasia conditions, but they have been
classified into two basic groups – group A & B. Cicatricial
alopecias have been linked with the group B ectodermal dysplasia
syndromes.
Ichthyosis
Ichthyosis is a group of cutaneous disorders characterized by increased
or aberrant keratinisation, resulting in non-inflammatory scaling
of the skin. Many different metaphors have been used to describe
the appearance and texture of the skin in the various types and
stages of ichthyosis, for example alligator, collodion, crocodile,
fish and porcupine skin. Most ichthyoses are genetically determined,
while a few may be acquired and develop in association with various
systemic diseases or be a prominent feature in certain genetic syndromes.
Autosomal recessive ichthyosis – congenital (inherited) ichthosiform
erythroderma (a non-specific designation for intense and usually
widespread reddening of the skin from dilatation of blood vessels,
often preceding, or associated with exfoliation) and lamellar ichthyosis – have
been found to initiate a particular inflammatory cicatricial alopecia
condition. Secondary dermatophytosis (any superficial fungal infection
caused by a dermatophyte or vegetable parasite and involving the
stratum corneum of the skin, hair and nails) and bacterial infections
are common as a secondary cause of the chronic suppurative folliculitis
and cicatricial alopecia in congenital ichthyosis.
KID syndrome represented by ichthyosis, keratitis and deafness
is mostly linked with papulopustular or suppurative folliculitis
in combination with extensive crusting; the condition finally progresses
to cicatricial alopecia. Ichythosiform erythroderma, the X-linked
prevailing form of Conradi-Hunermann chondrodysplasia punctata,
starts at birth and eventually develops to follicular atrophoderma,
an atrophy of the skin that may occur either in discrete localized
areas or in widespread areas, and cicatricial alopecia.
Incontinentia Pigmenti
Incontinentia pigmenti, a rarely occurring X-linked dominant genodermatosis
(a skin condition of genetic origin), has been reported to induce
cicatricial alopecia. The disorder may get underway as skin lesions
in utero when the child is still in the mother’s womb, or
appear as linear arrays of vesicles a little later in infancy. The
lesions or abrasions go through various changes to a verrucous and
hyperpigmented stage and ultimately trigger scarring alopecia. The
reported ‘rate of occurrence’ of cicatricial alopecias
is 30 percent of all initially symptomatic cases of incontinentia
pigmenti.
The other key features of incontinentia pigmenti include dental
and nail abnormalities, and mental retardation in about 1/3rd of
the cases. This X-linked skin disorder shows male lethality. The
incontinentia pigmenti gene is in band q28 on the X chromosome.
Mothers with incontinentia pigmenti have an equal chance of having
a normal or incontinentia pigmenti daughter or a normal son. The
incontinentia pigmenti sons die before birth. Incontinentia pigmenti
is also known as Bloch-Sulzberger syndrome.
Aplasia Cutis Congenita
Another, sometimes inherited, disorder leading to scarring alopecia
is aplasia cutis congenita. The condition presents itself as thin,
parchment-like scars over the scalp. The scars are of various shapes
and sizes and can occur anywhere, though often they are seen at
the center of the vertex in the middle of the “whorl” pattern
of scalp hair. As regards etiology (rather etiologies) of aplasia
cutis congenita, researche in the field has suggested a number of
causes. The most important among these being,
(i) Defective neural tube closure buring embryo development,
(ii) Intrauterine trauma and
(iii) Vascular occlusion with skin necrosis.
Aplasia cutis congenita has been linked with a variety of congenital
abnormalities, such as cleft lip and palate, congenital heart disease,
ectodermal dysplasias, genitourinary abnormalities, mental retardation,
terminal transverse limb defects and trisomy 13 syndrome. Remedial
measures include surgical removal and use of engineered skin.
Secondary
scarring alopecia - miscellaneous
Apart from the aforementioned categorized secondary scarring alopecia
conditions, studies reveal the existence of some hair loss disorders
that are again consequences of some other abnormalities or ailments
of the body. These conditions, however, could not be assigned any
specific group or category and have been assembled as miscellaneous
disorders.
Poems Syndrome
Poems syndrome is a chronic, progressive multi-system disorder
of obscure etiology characterized by,
• Polyneuropathy (a disease process involving a number of peripheral nerves)
• Organomegaly (abnormal enlargement of the viscera),
• Endocrinopathy (a disorder in the function of an endocrine gland and
the consequences thereof)
• Monoclonal gammopathy (any one of a group of disorders due to proliferation
of a single clone of lymphoid or plasma cells) and
• Skin changes sometimes including scarring alopecia.
Patients afflicted by Poems Syndrome have been identified with
a superimposing cicatricial alopecia condition, characterized by
erythema (unusual redness) and follicular pustules. In this particular
case, the plasmacytoma (malignant tumour of plasma cells, very similar
to a myeloma) was found to trigger the alopecia condition. Scalp
biopsy confirmed the occurrence of cicatricial alopecia with infiltration
of plasma cells and mast cells. Tissue culture findings were also
positive for the presence of Staphylococcus though its involvement
in the scarring alopecia of poems syndrome is not clear.
Lipedematous Alopecia
Lipedematous alopecia is a hair loss disease that is characterized
by the presence of thick, indurate subcutaneous fat. An occasionally
pruritic condition, palpation (medical diagnosis by touching) establishes
the softness of the involved scalp. Biopsies exhibit follicular
atrophy, follicular plugging and the presence of subcutaneous fat
with or without fibrosis.
Porokeratosis
Porokeratosis of Mibelli is an annular (like or forming a ring)
expanding abrasion that has a keratotic rim. Thus, while the central
area is already atrophic (wasted), the lesional growth is restricted
to the periphery, rather the expanding rim. The growing border is
distinguished by the presence of a column of parakeratosis that
represent a mutant clone of cells. The expanding column of parakeratosis
lies at 45-degree angle and points to the central dyskeratotic cells
(i.e., to the cornoid lamella). The parakeratosis probably disrupts
the hair follicle structure and effectively destroys it.
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