Histopathologic Spectrum of Alopecia.

Umamaheswari, - (2007) Histopathologic Spectrum of Alopecia. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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INTRODUCTION : Hair has no vital function in man and is not required for our physical existence. It plays a role in providing protection and serves as a vehicle for the application of medications and cosmetics. In forensic medicine, the analysis of hair is useful in identification and for the detection of various poisons. However, its most important function lies in the maintenance of an individual’s social and psychological equilibrium. Alterations in the quantity and quality of hair have a great impact on behaviour and social interactions. Diseases of the hair are not generally associated with mortality, but are responsible for significant morbidity. While most men with a family history of alopecia are able to reconcile themselves to a bald head, the situation in women is different. Hair loss in women, causes as much anguish as the growth of facial or body hair in excess of culturally acceptable norms. About 50 to 100 hairs are shed every day from the normal scalp. When the daily hair loss exceeds 100, it is known as alopecia. Alopecia is not uncommon and the prevalence rate is 1.7% of the population. Men and women are equally affected and a family history of the disorder is present in about 25% of patients. It may be one of the manifestations of a systemic disease or a disease entity in itself. The latter consists of a variety of clinicopathologic disorders. Hair follicles are classified as terminal, indeterminate and vellus depending on the thickness of the hair shaft. They also have a distinctive morphology according to the phase of the growth cycle. These consist of actively growing/anagen, involuting /catagen and resting/telogen hair follicles. In the past, standard textbooks of histology and dermatopathology have not provided details that make these structures easy to identifyg. The most recent dermatopathology textbooks and atlases have solved the problem to a large extent. Since scalp biopsies are infrequently received in the histopathology laboratory and conventional vertical sections have been replaced by horizontal sections it seemed necessary to study normal scalp biopsies in addition to those from patients with alopecia. AIMS AND OBJECTIVES : 1. To study scalp biopsies from normal individuals in order to be familiar with the types of hair follicles and the phases of the hair cycle. 2. To assess the histological changes in the various types of alopecia. 3. To evaluate the impact of combining vertical and horizontal sections in studying alopecia. MATERIALS AND METHODS : Scalp biopsies were received in the Histopathology department of PSG Institute of Medical Sciences and Research, Coimbatore, from 40 patients with alopecia, during the period July 2004 to February 2007. Except for 2 biopsies that were 3 mms in diameter, the rest were 4mm punch biopsies, taken from sites where the disease was active, yet not too advanced. This was usually at the periphery of the lesion. They were sent in 10% formalin and processed in an automatic tissue processor prior to paraffin embedding. Nine vertical sections were taken and mounted on 3 glass slides. The block was then melted and the tissue re-embedded with the subcutaneous tissue facing downwards and the epidermal aspect towards the technician in order to obtain horizontal sections. Serial 5μ sections were cut on a Leitz microtome with a disposable blade until the tissue was exhausted . Every 25th to 27th section was mounted on 3 separate glass slides and each slide had 4 levels,eg, 25,50,75,100, etc. One slide having the vertical sections and one slide each representing various levels were stained with haematoxylineosin (H-E). The others were stained with Verhoeff van Gieson(VVG) or Alcian blue/periodic acid-Schiff (AB/PAS) as required. CONCLUSIONS : Scarring and non-scarring alopecia were almost equally represented in this series. Lichen planopilaris was the commonest variant of scarring alopecia. It was possible to distinguish it from discoid lupus erythematosus by the absence of inflammation in the deep dermis, diffuse deposition of dermal mucin and extensive dermal scarring. But, in 2 cases there was an overlap of microscopic features and this underscores the need for immunofluorescence studies in cases of scarring alopecia. There were no cases of central, centrifugal scarring alopecia which is characterized by eccentric atrophy of the follicular epithelium and premature desquamation of the inner root sheath. This was seen in cases of scarring alopecia and in one case of androgenetic alopecia respectively, which raises the issue that these features may not be specific to central, centrifugal scarring alopecia. Unusual forms of secondary scarring alopecia- scleroderma, lichen sclerosus et atrophicus and necrobiosis lipoidica were also studied. Alopecia areata was the commonest cause of hair loss and was diagnosed on the presence of peribulbar inflammation and / or nanogen hair follicles. Although it is cumbersome, a more complete and thorough examination is possible by combining vertical and transverse sectioning of the same punch biopsy.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Histopathologic Spectrum ; Alopecia.
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 11 Aug 2017 02:59
Last Modified: 11 Aug 2017 02:59
URI: http://repository-tnmgrmu.ac.in/id/eprint/1321

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