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Secondary
scarring alopecia from neoplastic disorders
The NAHRS (North American Hair Research Society) has established
a connection between secondary scarring alopecia and neoplastic
disorders (abnormal, tumorous growth of tissues).
Malignant Disorders
Scarring alopecias have been associated with malignant disorders – both
primary and metastatic. Both primary and metastatic alopecia conditions
are presented as flesh-colored alopecic patches with irregular erythematous
plaques and nodules. The lesions appearing in primary malignancy
scarring alopecia are often mistaken for alopecia areata. In such
cases, biopsies are a great help in confirming the diagnosis. The
replacement of follicles by tumors leads to permanent alopecia.
Common malignancies inducing scarring alopecia include melanoma
(a tumor arising from the melanocytic system of the skin and other
organs), metastatic tumors (especially breast and renal carcinoma),
lymphomas, leukemic infiltrates and plasmacytoma (malignant tumour
of plasma cells, very similar to a myeloma). Even some forme frustes
(a partial, arrested, or inapparent form of disease) of cutaneous
T-cell lymphoma present themselves with alopecia and include those
that have been histologically identified as alopecia mucinosa, basaloid
follicular hyperplasia (the abnormal multiplication or increase
in the number of normal cells in a regular arrangement in a tissue)
and syringolymphoid hyperplasia. Vascular or adnexal tumors too
manifest scalp lesions with associated alopecia.
Hamartoma or Benign Disorders
Hamartoma is tumor like but non-neoplastic overgrowth of tissue
that is disordered in structure.
Non-neoplastic overgrowth of tissue, which is very often disordered
in structure and growth pattern, many a times produces different
alopecia conditions. Syringoma is a benign tumor of the sweat glands
which is usually multiple and results from malformation of sweat
ducts. It is uncommon but affects females more than males. It is
most likely to appear at adolescence, and further lesions may develop
during adult life. Syringoma can cause a non-scarring, but permanent
form of alopecia, which shows a diffuse pattern of hair loss. Outwardly,
the alopecia state shows no other signs except for hair loss. This
scarring disorder shares features with alopecia areata, female pattern
hair loss as well as other end-stage scarring alopecias.
Generalized follicular hamartoma is another such benign disorder
provoking a progressive permanent alopecia. Apart from scalp skin,
the condition can affect other hair bearing parts of the body. Clinical
features of the disorder include localized alopecic patches or plaques.
The hair follicles undergo abnormal growth (and show symptoms of
basaloid hamartoma) and do not support hair fiber formation. Biopsy
tests reveal the presence of empty follicles and follicular cysts.
Tests also confirm the absence of concentric fibroblast-rich stroma
and papillary (papilla is a projection occurring in various animal
tissues and organs) mesenchymal (mesenchyme is embryonic tissue
of mesodermal origin) bodies of trichoepithelioma. Trichoeptheliomas
are multiple small benign nodules, occurring mostly on the skin
of the face, derived from basal cells of hair follicles enclosing
small keratin cysts.
Organoid Nevus (Nevussebaceous of Jadassohn) is a complex hamartoma
that affects the hair follicles, the sebaceous glands, epidermal
layers and even the sweat glands. This hamartoma condition induces
cicatricial alopecia in people irrespective of age and is even common
among infants. At birth, it appears as a hairless, yellow, waxy
patch or plaque on the scalp, forehead, or face. With advancing
age, the lesions undergo many changes – from patches/plaques
to verrucas (covered with outgrowths or benign tumours of basal
cell of skin, which is usually the result of the infection of a
single cell with wart viruses or Papilloma viruses) to tumors. These
changes are reflected in reduced numbers of terminal follicles and
increased or enlarged “primitive” follicle-like growths
incapable of producing hair fiber.
Secondary
scarring alopecias from granulomatous conditions
Granulomatous (firm, tumor like granulation formed as a reaction
to chronic inflammation) conditions too are known to instigate scarring
alopecias. Two conditions – Sarcoidosis and Necrobiosis Lipoidica – are
particularly interesting.
Sarcoidosis
Sarcoidosis is a systemic disease of unknown etiology in which
there are chronic inflammatory granulomatous lesions in lymph nodes
and other organs. It can lead to a rare form of a patchy, progressive
alopecia. The characteristic sarcoidal patches are flesh colored
or telangiectatic (a permanent dilation of pre-existing blood vessels – capillaries,
arterioles, venules – creating small focal red lesions, usually
in the skin or mucous membranes) or similar to yellow indurated
(hardened) plaques.
Histologic studies reveal the presence of scattered, superficial and also
deep, naked sarcoidal granulomas (localised nodular skin inflammation showing
as small reddish raised areas of skin). The follicular units too are diminished.
The biopsy tests also trace the presence of chronic lymphocytic periadnexal
and perifollicular infiltrate. Treatment options for cutaneous sarcoid include
topical, intralesional, and parenteral steroids. Anti-malarials and cytoxic
drugs have also been successfully used to treat the scarring alopecia.
Necrobiosis Lipoidica
Necrobiosis lipoidica is a degenerative disease of the dermal connective
tissue characterised by the development of erythematous papules
or nodules in the pretibial area. The papules form plaques covered
with telangiectatic vessels. More than half of the affected patients
have diabetes.
This rare disease prompts an alopecia condition, which is characterized
by the presence yellow-red indurated alopecic plaques. The inflammation
spreads rather slowly and in the advanced stage, the expansile granuloma
replaces the normal dermis and its adnexal structures. Corticosteroids
promise a respite from the condition.
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