Male androgenetic alopecia (Part II)

Abstract

Androgenetic alopecia only becomes a medical problem when the hair loss is excessive, premature and distressing to the patient. A number of medical treatments aimed at arresting the progression of the hair loss have become available in recent years, and surgical treatments are constantly being refined. The three distinct aims of therapy for male androgenetic alopecia are: to arrest further progression, to stimulate regrowth and to conceal the hair loss. Topical minoxidil stimulates regrowth but may or may not arrest further progression. Oral 5 alpha reductase inhibitors arrest further progression but may or may not stimulate regrowth. Hair transplantation, coloured hair sprays, wigs and toupees conceal the hair loss but do not stimulate regrowth or arrest further hair loss. Hair transplantation redistributes hair more evenly over the scalp. Substantial efforts have been undertaken to refine the methods used to evaluate therapeutic response and define acceptable primary and secondary endpoints for clinical trials. Currently the US Federal Drug Association (FDA) accepts numerical hair count data and patient subjective response as primary endpoints and standardized scalp photography as a secondary endpoint. This difficulty in evaluation of outcome is magnified in clinical practice where hair counts are not feasible and the clinician relies overly on patient subjective assessment. Serial scalp photography is especially valuable in this setting.

Androgenetic alopecia: a review

“…The regional specificity of androgen action is also partly explained by in vitro experiments, where androgen stimulation of scalp DPCs induced TGF-β1 production, while stimulation of beard DPCs induced IGF-1 as a second messenger [24]. Itami et al observed that the synthetic androgen R1881 suppressed keratinocyte growth in the coculture of AR-overexpressing human DPCs from AGA and normal human keratinocytes, through androgeninducible TGF-β1 [22,25].…”

Androgenic alopecia updates

“…The weight of hair is influenced by factors such as hair density, hair growth rate, and hair thickness. These studies demonstrate finasteride's capacity to counteract the shrinking process, resulting in longer and thicker hair, maybe with an increased growth rate [52] . 2.…”

Prevalence of Aquatic Insects and Arsenic Concentration Determine the Geographical Distribution of Mycobacterium ulcerans Infection

“…In addition, the spread of BU is enhanced by a lower death rate of humans. Equation (11) shows that the prevalence of BU in humans depends on the biting rate of water-bugs, their mortality rate and As concentration in the environment. For BU, a is relatively smaller than m, thus the prevalence of BU (see equation (11)) in humans and MU in waterbugs (equation (15)) increases for R 0 .…”

“…Recreational activities near rivers where MU persists could lead to costly BU infection. Considering the fact that the cost of swimming related illnesses in only two beaches of Orange County in California, for example, is estimated to be over USD 3 million per year [11], an outbreak of BU could lead to substantially higher health costs since water recreation is enjoyed by a greater proportion of the population in developed countries.…”