| Senile or senescent alopecia |
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Aging leads to reduced hair density and thinner fibers leading to hair loss.
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Shares various features with AGA.
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Begins later in life, (70 years old)
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Distinguished by the synchronization of HF miniaturization
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Does not respond to 5α-reductase inhibitor treatment.
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The impact of aging dermal environment on HF is unclear.
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However, evidently aging scalp shows striking structural and biological changes in HF environment that affect hair growth, and
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A phenomenon of gradual thinning of hair with age due to increasing number of HF switching from anagen, to telogen
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[12] |
| Anagen effluvium (AE) |
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Characterized by the abrupt shedding of anagen hairs affected by an acute insult.
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Commonly observed as a result of anticancer treatment, heavy metal poisoning or radiotherapy.
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Associated with AA, pemphigus vulgaris, local traumas and infections.
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Diagnosis is based on history and a positive pull test with dystrophic anagen hairs.
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Direct damage to the mitotic/metabolic activity of the HF.
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Target the desmosomal proteins, which are overexpressed in the HF epithelium.
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Hair shedding may result from cleavage of the ORS.
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[13] |
| Telogen effluvium (TE) |
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A wide range of factors and diseases can induce hair loss through various mechanisms.
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Common induction factors include stress, nutritional deficiencies, bariatric surgeries, hormonal imbalances in pregnancy and menopause, thyroid dysfunction, diabetes, autoimmune diseases, polymyositis, Sjögren's syndrome, febrile or infectious diseases, neoplastic diseases, chronic poisoning, certain drugs and chronic exposure to low-dose toxic agents
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[14,15]. |
| Alopecia secondary to SLE |
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Hair loss in SLE can be either diffuse non-CA, such as TE, AGA, AE, and lupus hair, or patchy non-CA, such as AA, the most common type of alopecia observed in SLE.
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|
[16]. |
| Trichotillomania (TTM) |
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Often coexists with skin picking disorder (SPD),
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Characterized by repeated pulling out of hair resulting in hair loss
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In SPD picking at skin results in tissue damage.
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Both are considered under repetitive behavior disorders and often lead to significant psychosocial impairment
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Reward seeking and loss/harm avoidance play important roles in human behavior, and when there is dysfunction in reward processing, maladaptive behaviors, such as TTM and SPD may occur.
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[17,18] |
| Traction alopecia (TA) |
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Majorly affects individuals who wear various forms of traumatic hairstyling for a prolonged period of time.
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Risk is increased by extent of pulling and duration of traction, and the use of chemical relaxation.
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The frequent use of tight buns or ponytails, the attachment of weaves or hair extensions, and tight braids are believed to be the highest risk hairstyles.
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TA can also occur in the setting of religious and occupational traumatic hairstyling.
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Without appropriate intervention TA may progress into an irreversible CA if traumatic hairstyling persists.
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TA is characterized by marginal alopecia and non-marginal patchy alopecia features and distinguished by its preservation of the frontal and/or temporal rim, dubbed the “fringe sign and detection of the ongoing traction by the presence of hair casts through a dermoscopy.
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|
[19,20] |
| Lipedematous scalp (LS) and lipedematous alopecia (LA) |
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[21]. |
