Hair Loss - Hair Structure

Hair Structure Hair consists of two parts- the hair follicle and the hair shaft. It is composed of a protein called keratin. Each hair strand has three layers. The innermost layer, or medulla is found in large, thick layer. The cortex – or the middle layer-gives the hair its strength, colour and texture. The outermost layer, cuticle, protects the cortex. The hair root is enclosed within the hair follicle, and the dermal papilla lies at its base. The root is nourished by the bloodstream, which helps the new hair to sprout up. This hair follicle is influenced by the action of the male hormones or androgens which causes it to progressively shrink and thin down in genetically predisposed people. Hair growth is a cyclical process. It has three alternating phases – Anagen, Catagen and Telogen. Anagen ( Growing phase) lasts for 3-5 years, catagen for 2 weeks and telogen ( resting phase) for 3 months. The usual ratio of anagen : telogen is 12:1. Normal hair shedding occurs in the telogen phase. The sensitivity of dermal papilla to androgenetic hormones is increased in alopecia patients. The increased level of androgens lead to shortening of the anagen phase of the hair cycle without affecting the telogen stage. As a result of this, the ratio of anagen: telogen decreases from the usual 12:1. Thus, the number of hair in anagen phase ( which cover the scalp) keeps on progressively decreasing with every cycle and telogen or the resting hair keeps on increasing resulting in bald spots on the scalp. Diagram of hair structure

Distribution of Hair

Hair is present all over the body except in the skin of hands and feet , lips and genitals and on the end of the fingers and toes. About five million hair follicles are present in our skin while only 2% of them are present on the head. The density of hair is maximum in face (800 hairs/cm2) followed by head, face trunk and extremities.

Causes of Hair loss

1. Noncicatricial Alopecia

Physiological: alopecia of infants, post-partum alopecia. Alopecia areata Telogen effluvium Infections: dermatophytosis, bacterial and spirochaetal infections Chemicals & drugs: Thallium/heparin/cancer chemotherapy/hypervitaminosis A Physical trauma (self induced): trichotillomania, scratching of neurodermatitis Endocrinopathy: Hypothyroid, hyperthyroid, hypoparathyroid, hyperparathyroid Physical agents: mild trauma, epilating dose of radiotherapy, short term hair traction Systemic diseases: systemic lupus erythematous, dermatomyositis, sarcoidosis, langerhan’s cell histocytosis, amyloidosis.

2. cicatricial Alopecia

Physical trauma: X-ray overdose burn, long term traction on hair Infections:Bacterial-leprosy, tubeculosis, late secondary and tertiary syphilis, folliculitis     decalvans, dissecting folliculitis, carbuncles Dermatophytosis: zoonotic fungi Viral: herpes zoster, recurrent herpes simplex Chemical injury: Caustics Cutaneous diseases: discoid lupus erythmatous, pseudopelade, follicular lichen planus Destructive neoplasms and granulomas Psychogenic conditions: neurotic excoriating tactile injury to skin

3. Miscellaneous

Androgenic alopecia (common baldness) Congenital alopecia Hair shaft abnormalities: monolithix, pili annulati, wooly hair

Evaluation of Hair Loss

The following points are kept in mind while evaluating the hair loss.

Rate of linear growth Hair shaft diameter Hair density Hair – cycle status (anagen: telogen ratio or %age of anagen-VI hairs) Pigment content

History and Examination

Time period of hair loss (congenital, acquired) Progression of hair loss, remissions if any (alopecia aerate may shoe remission) Any positive family history for hair loss. History of gastrointestinal dysfunction, dysfunction of the thyroid gland, or psychological disorders. History of recent surgical intervention, blood loss, chronic illness. All medications Drugs, particularly anticancer agents, anticoagulants, antoconvulsants, thyroid drugs, ß-blockers, and trycyclic antidepressants, can cause diffuse thinning. In females, the menstrual and obstertric history. Hair care routine and hair products applied.

Treatments available for hair loss:

Management of Male Pattern Baldness

Medical treatment Finasteride Minoxidil Multi vitamins Hair oils Herbal treatment Acupuncture Steroids Homeopathy Laser Therapy Cosmetic aids- wiglets, hair weaves, hair extensions, Pigmented powders, lotions and hair sprays.

Surgical treatment – Hair Transplant

Options –

Punch Transplant Scalp Reduction Scalp Extensions Artificial hair transplants Follicular Unit Hair Transplant      STRIP      FUE ( Follicular unit Extraction) Source : http://www.akclinics.com/hair-loss.php

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