Dermatology on-line journal
Volume 14 Number 7
July 2008

Radiation-induced temporary alopecia after embolization of cerebral aneurysms
Nuria Marti, et al

edited for blog

....Alopecia probably appeared due to prolonged exposure to radiation in the same area of skin (occipital-temporal-parietal) and limited variation in the direction of application. Excluding the diagnosis of alopecia areata may be difficult because the bald patch is devoid of inflammatory signs and hair loss is characterized by dystrophic hair. The localization of the bald patches along the scalp margins with an ophiasis pattern occured because this scalp region received the highest doses of radiation therapy during embolization [2, 3, 5].

Irradiation-induced epilation depends on the high susceptibility of anagen follicles to radiation. Loss of dystrophic hairs (anagen effluvium) due to acute damage to actively dividing matrix cells of anagen follicles is followed by telogen shedding due to premature catagen entry of follicles in late anagen subphases at the time of damage. Complete hair regrowth generally occurs 2 to 4 months after irradiation.

The cutaneous epidermal growth factor network: Can it be translated clinically to stimulate hair growth?
Doru T Alexandrescu MD, et al
Dermatology Online Journal 15:1

Edited Exerpt:

In summary, current data support the fact that EGF is central in the regulation of hair morphogenesis, with its cyclical on/off switch being important for the progression of the hair cycle. Cooperation with other molecules appears to be necessary; the downregulation of some effectors (TGF-á), but synergism with others (FGF-5) result in a longer hair phenotype [17]. On the other hand, continuous expression of EGF, or TGF-á, although producing a wavy phenotype, impedes the growth of hair. Therefore, cyclic variations in the level of EGFR, which is a key intermediate in signal transmission, may result in hair regrowth and produce new hair formation. Conversely, continuous EGFR blockage would interfere with new hair formation and a severe decrement in its function can even result in hair loss. The principle of cycling and maintenance of a low level of hair regrowth stimulation has proven biological relevance. It was demonstrated as a paradigm by the results of studying the stimulation/inhibition for androgenic blockade in prostate cancer through using a LHRH agonist administered continuously and by ensuring contraception through providing uniform levels of the hormones that otherwise produce ovulation when subjected to brisk variations.

© 2009 Dermatology Online Journal

Dermatol Clin.1990;8:367

Hair loss treatment with minoxidil

DeVillez RL.

Topical minoxidil is a hair loss treatment agent that stimulates the hair follicle..... Less than 5% of the applied dose is absorbed. The therapeutic effect on hair regrowth is demonstrated for pattern hiar loss in males and females, by a computer-assisted image analysis counting technique of nonvellus hairs from a photographic print. Patients with severe alopecia areata respond poorly to topical minoxidil treatment. The most common adverse reactions are limited to irritant and allergic contact dermatitis on the scalp. The use of retinoic acid with topical minoxidil has been disappointing relative to the increase in systemic exposure. The value of topical minoxidil as an adjunct for the hair transplant procedure and its effect on hair loss from chemotherapy .

Rev Stomatol Chir Maxillofac. 2007;108:411

Skin expansion in cicatricial alopecia of the scalp

Drissi Qeytoni H, et al

INTRODUCTION: Skin expansion technique used to increase the hair surface available at the scalp level was a major breakthrough in the surgical treatment of important cicatricial alopecia. This article had for aim to define the importance and limits of this technique in the treatment of hair loss. snip.. The rate of major complications leading to total failure of the process reached 5.5%. The final result was considered good in 90% of the cases. DISCUSSION: The results demonstrate that skin expansion technique is a simple, reliable, and efficient method in the healing of important cicatricial hair loss of scalp. It enables a wider use of the classical local flap technique, by expanding the surface and vascularization allowing for a direct suturing of the donor site. Skin expansion holds an important place in the treatment of significant skin cicatricial alopecia, since it represents the only surgical solution when the alopecia area exceeds 50 cm2.

Hair regrowth blog

Dr Proctor treats hair loss

Semin Cutan Med Surg. 2009;28:11

Chemotherapy-induced hair loss.
Trüeb RM.

Few dermatologic conditions carry as much emotional distress as chemotherapy-induced hair loss (CIA). The prerequisite for successful development of strategies for CIA prevention is the understanding of the pathobiology of CIA. The incidence and severity of CIA are variable and related to the particular chemotherapeutic protocol. CIA is traditionally categorized as acute diffuse hair loss caused by dystrophic anagen effluvium; however, CIA presents with different clinical patterns of hair loss. When an arrest of mitotic activity occurs, obviously numerous and interacting factors influence the shedding pattern. The major approach to minimize CIA is by scalp cooling. Unfortunately, most published data on scalp cooling are of poor quality. Several experimental approaches to the development of pharmacologic agents are under evaluation and include drug-specific antibodies, hair regrowth cycle modifiers, cytokines and growth factors, antioxidants, inhibitors of apoptosis, and cell-cycle and proliferation modifiers. Ultimately, the protection should be selective to the hair follicle; for example, topical application, such that the anticancer efficacy of chemotherapy is not hampered. Among the few agents that have been evaluated so far in humans, AS101 and minoxidil were able to reduce the severity or shorten the duration of CIA, but could not prevent CIA.

Br J Dermatol.2009;161:228

Epidermal stem cells: practical perspectives and potential uses.
Abbas O, Mahalingam M.

Blog edited

.....the epidermis and the hair follicle undergo a perpetual cycle of regrowth, regression and rest. Stem cells in the epidermis not only ensure the maintenance of epidermal homeostasis and hair regeneration and regrowth, but also contribute to repair of the epidermis after injury. These stem cells lie within specific niches in the hair follicle and the epidermis. The availability of monoclonal antibodies that can be used on formalin-fixed paraffin-embedded tissue has greatly facilitated the use of this methodology as an adjunct to uncovering stem cell niches. In this review, we attempt to provide an overview of the potential markers available to identify and study stem cells in an effort to providing a better understanding of the pathogenesis of skin diseases including disorders of hair loss and malignancies. The potential uses of these markers in prognosis and in expanding the therapeutic options in several disorders, such as in >hair loss treatment, will also be addressed.

Exp Dermatol. 1998;7:289

Equine alopecia areata autoantibodies target multiple hair follicle antigens and may alter hair growth. A preliminary study.Tobin DJ, et al

Several cases of hair loss due to an alopecia areata like disease exist in mammalian species.....snip... The current preliminary study was conducted to determine whether a horse with AA-like hair loss contained circulating antibodies to HE The pathogenic potential of these antibodies was examined by passive transfer into anagen skin of C57BL/ 10 black mice. snip... IgG fractions of serum obtained from an "AA" horse and from a normal control horse were injected into anagen murine skin. Histologically, normal hair regrowth was observed in mice injected with normal equine IgG. By contrast, hair did not re-grow in an area around the injection site of AA-treated mice even 13 weeks after first injection. This skin contained telogen follicles, most often without associated shafts, despite the presence of anagen HF in the remaining dorsum skin. While this study is preliminary, it demonstrates for the first time that antibodies to HF antigens are a feature of AA-like hair loss in horses...snip... Further, we provide in this pilot study preliminary evidence that such antibodies may disrupt hair re-growth when passively transferred into mice, supporting the view that anti-HF antibodies in AA may have pathogenic potential.

Vet Rec.1988 19;123:533

Folic acid therapy for alopecia in a Charolais calf.
Bouvet A, et al

A ... Charolais calf which had a history of progressive hair loss and clinical signs, including crusts and brown patches similar to those in folic acid deficiency syndrome in man, was subjected to folic acid therapy. Daily oral administration of folic acid (1 mg/kg/day) resulted in the gradual disappearance of the crusts and patches within two weeks and a steady growth of hair and recovery to a normal state within two months. Folic acid, which is required for cellular turnover in a variety of tissues and organs including the hair follicle, may serve as an effective therapeutic agent in some types of hair loss....

J Invest Dermatol. 2009 May;129(5):1243-57. Epub 2008 Dec 4.

Hair follicle stem cell-specific PPARgamma deletion causes scarring alopecia.
Karnik P, et al

Primary cicatricial or scarring alopecias (CA) are a group of inflammatory hair loss disorders characterized by the permanent destruction of the hair follicle. The current hair loss treatment options are ineffective in controlling disease progression largely because the molecular basis for CA is not understood. Microarray analysis of the lymphocytic CA, Lichen planopilaris (LPP), compared to normal scalp biopsies identified decreased expression of genes required for lipid metabolism and peroxisome biogenesis. Immunohistochemical analysis showed progressive loss of peroxisomes, proinflammatory lipid accumulation, and infiltration of inflammatory cells followed by destruction of the pilosebaceous unit. The expression of peroxisome proliferator-activated receptor (PPAR) gamma, a transcription factor that regulates these processes, is significantly decreased in LPP. Specific agonists of PPARgamma are effective in inducing peroxisomal and lipid metabolic gene expression in human keratinocytes. Finally, targeted deletion of PPARgamma in follicular stem cells in mice causes a skin and hair phenotype that emulates scarring hair loss. These studies suggest that PPARgamma is crucial for healthy pilosebaceous units and it is the loss of this function that triggers the pathogenesis of LPP. We propose that PPARgamma-targeted therapy may represent a new strategy in the treatment of scaring alopecias.