What’s new in hair — January 2017 | Dr. Yuval Ramot
Efficacy of superficial cryotherapy on the eyebrows of patients with alopecia universalis also treated with contact immunotherapy on the scalp: a prospective, split-face comparative study
Int J Dermatol. 2017 Feb;56(2):184-189. doi: 10.1111/ijd.13533.
Cryotherapy is used for a wide range of indications in dermatology, being a simple and non-invasive treatment. There is also limited evidence that it might be effective in alopecia areata (AA). In this manuscript, Cohe and Lee conducted a prospective, split-face comparative study to assess the efficacy of superficial cryotherapy n 20 patients with AA of the eyebrows. This treatment was assessed following diphenylcyclopropenone (DPCP) immunotherapy on the scalp. The use of cryotherapy led to a significant increase in the density and thickness of hair. No treatment-related side effects were noted during this study, and the authors reported on good compliance of the patients. This study should be further validated in larger cohorts; however, cryotherapy might be considered as a therapeutic modality for AA of the eyebrows.
Oxidative damage control in human (mini-) organ: Nrf2 activation protects against oxidative stress-induced hair growth inhibition
J Invest Dermatol. 2016 Oct 1. pii: S0022-202X(16)32466-6. doi: 10.1016/j.jid.2016.08.035. [Epub ahead of print]
The production of reactive oxygen species (ROS) can affect a large number of biological functions in different organs, including the hair follicle (HF). Indeed, the accumulation of ROS in the HF has been linked to androgenetic alopecia and HF senescence. In this study, Haslam et al. evaluated the role of Nrf2, a central transcription factor in controlling the redox balance, in preventing oxidative damage in the HF. Using the HF organ culture model, they showed that activation of Nrf2 led to enhanced expression of genes responsible for limiting ROS production. These included, for example, the reduction of reactive quinones, direct clearance of ROS, glutathione homeostasis, cytoprotection, and NADPH production. Together, these effects have phenotypic implications, preventing the reduction in hair growth and catagen development following oxidative stress. Therefore, activation of Nrf2 may be a promising treatment modality for the prevention of hair loss in several clinical settings, including chemotherapy- and radiation-induced alopecia and androgenetic alopecia.
Allergy. 2017 Jan 19. doi: 10.1111/all.13128. [Epub ahead of print]
Atopic dermatitis is known to increase the odds for having alopecia areata (AA) by up to 7.5 times. However, this information is based on small-scale studies, with less than 10,000 participants. In this study, Drucker et al. took advantage of the Nurses’ Health Study 2 (NHS2) to perform the first prospective study to examine the association of incident AA and atopic dermatitis. This large-scale study included 87,406 participants, and over a 2-year follow-up found 147 incident cases of AA. Multivariate models revealed that atopic dermatitis is associated with an odds ratio of 1.8 for developing AA, confirming previous results that showed that atopic dermatitis is a risk factor for developing AA in adulthood. The authors suggest that this association may have therapeutic implications, since both conditions have been found to respond to JAK-STAT inhibition. Therefore, patients who suffer from both condition can especially benefit from such a therapeutic approach.
Stress-induced premature senescence of dermal papilla cells compromises hair follicle epithelial-mesenchymal interaction
J Dermatol Sci. 2017 Jan 5. pii: S0923-1811(17)30026-9. doi: 10.1016/j.jdermsci.2017.01.003. [Epub ahead of print]
The function and growth of the hair follicle (HF) is dependent on normal epithelial-mesenchymal interaction. Therefore, pathological changes in the dermal papilla (DP) cells, which constitute the specified mesenchymal cells of the HF, can have major effects on normal regeneration of the HF. In this work, Huang et al. aimed to examine how senescence of DP cells, which was achieved using a newly developed method of oxidative stress challenge, can affect HF functions. Using this method, they could demonstrate that the premature senescence of DP cells affects the interaction between the HF epithelium and the DP cells, resulting in impaired proliferation and differentiation of the HF epithelial cells, and compromising the activation of the HF stem cells. Such mechanism may be part of the underlying pathogenesis of hair loss disorders that appear with age, such as androgenetic alopecia or female pattern hair loss.
Exp Dermatol. 2017 Jan 17. doi: 10.1111/exd.13287. [Epub ahead of print]
The insulin-like growth factor (IGF1) pathway is important for a large number of biological processes, and has also been shown to take part in hair follicle (HF) homeostasis. However, previous studies examining the role of this pathway in HF growth has resulted in inconsistent results. Therefore, in this study, Castela et al. developed an inducible murine model of IGF1R deletion limited to K15+ cells. Using this model, they could show that there was an earlier entrance into hair cycle together with a prolonged anagen stage. The loss of IGF1R also changed the expression of BMP-4 and MED1 in the HF, leading to impaired downstream signalling by these negative regulators of the HF cycle. Taken together, this study clearly shows the importance of the IGF1R signalling to the HF cycle.
Br J Dermatol. 2017 Jan 23. doi: 10.1111/bjd.15311. [Epub ahead of print]
In the March 2016 edition of “What’s new in hair” we reported on a questionnaire study that suggested that leave-on facial skin products may be related to frontal fibrosing alopecia (FFA) in women (Aldoori et al., Br J Dermatol, 2016). In the current study, Debroy-Kidambi et al. repeated this questionnaire study in men with FFA. Seventeen men with FFA and 73 controls were assessed. All men with FFA reported using facial moisturisers compared to 40% of the control group, and primary sunscreen use was significantly more common in men with FFA than in controls. These results support the previous observations in women that there is a connection between the use of leave-on facial skin care products and FFA.