Topical Immunotherapy in the Treatment of Chronic Severe Alopecia Areata

Guidelines for the Management of Patients with Alopecia Areata in Korea: Part I Topical and Device-based Treatment

BACKGROUND

Alopecia areata (AA) is a chronic disease with an unpredictable disease course and severe psychological impact.

OBJECTIVE

To provide evidence- and consensus-based insights regarding the treatment of patients with AA in Korea.

METHODS

We searched for relevant studies on the topical and device-based treatment of AA in the literature from inception until May 2021. Evidence-based recommendations were also prepared. The evidence for each statement was graded and classified according to the strength of the recommendations. Hair experts from the Korean Hair Research Society (KHRS) voted on the statements, and an agreement of 75% or greater was considered as consensus.

RESULTS

Currently, there remains a scarcity of topical treatments, which is supported by robust evidence from a number of high-quality randomized controlled trials. Current evidence supports the efficacy of topical corticosteroids, corticosteroid intralesional injection, and contact immunotherapy in AA patients. Topical corticosteroids and contact immunotherapy are recommended for pediatric AA. A consensus was achieved in 6 out of 14 (42.8%), and 1 out of 5 (20.0%) statements pertaining to topical and device-based treatments in AA, respectively. The expert consensus was from a single country, and the study may not cover all the treatments used.

CONCLUSION

The present study provides up-to-date, evidence-based treatment guidelines for AA based on the consensus reached among experts after considering regional healthcare circumstances, adding diversity to the previous guidelines.

Alopecia Areata: a Comprehensive Review of Pathogenesis and Management

Alopecia areata is a common hair loss condition that is characterized by acute onset of non-scarring hair loss in usually sharply defined areas ranging from small patches to extensive or less frequently diffuse involvement. Depending on its acuity and extent, hair loss is an important cause of anxiety and disability. The current understanding is that the condition represents an organ-specific autoimmune disease of the hair follicle with a genetic background. Genome-wide association studies provide evidence for the involvement of both innate and acquired immunity in the pathogenesis, and mechanistic studies in mouse models of alopecia areata have specifically implicated an IFN-γ-driven immune response, including IFNγ, IFNγ-induced chemokines and cytotoxic CD8 T cells as the main drivers of disease pathogenesis. A meta-analysis of published trials on treatment of alopecia areata states that only few treatments have been well evaluated in randomized trials. Nevertheless, depending on patient age, affected surface area and disease duration, an empiric treatment algorithm can be designed with corticosteroids and topical immunotherapy remaining the mainstay of therapy. The obviously limited success of evidence-based therapies points to a more important complexity of hair loss. At the same time, the complexity of pathogenesis offers opportunities for the development of novel targeted therapies. New treatment opportunities based on the results of genome-wide association studies that implicate T cell and natural killer cell activation pathways are paving the way to new approaches in future clinical trials. Currently, there are ongoing studies with the CTLA4-Ig fusion protein abatacept, anti-IL15Rβ monoclonal antibodies and the Janus kinase inhibitors tofacitinib, ruxolitinib and baricitinib. Ultimately, the options available for adapting to the disease rather than treating it in an effort to cure may also be taken into consideration in selected cases of long-standing or recurrent small spot disease.

The role of lymphocytes in the development and treatment of alopecia areata

Alopecia areata (AA) development is associated with both innate and adaptive immune cell activation, migration to peri- and intra-follicular regions, and hair follicle disruption. Both CD4(+) and CD8(+) lymphocytes are abundant in AA lesions; however, CD8(+) cytotoxic T lymphocytes are more likely to enter inside hair follicles, circumstantially suggesting that they have a significant role to play in AA development. Several rodent models recapitulate important features of the human autoimmune disease and demonstrate that CD8(+) cytotoxic T lymphocytes are fundamentally required for AA induction and perpetuation. However, the initiating events, the self-antigens involved, and the molecular signaling pathways, all need further exploration. Studying CD8(+) cytotoxic T lymphocytes and their fate decisions in AA development may reveal new and improved treatment approaches.

Treatment of alopecia areata with squaric acid dibutylester

Squaric acid dibutylester is a topical sensitizing agent utilized for the treatment of alopecia areata. The mechanism of action is not fully understood, but is believed to redirect the inflammatory response by invoking allergic contact dermatitis. Several studies have compared the efficacy of squaric acid dibutylester to other treatments vs placebo with favorable results. This contribution reviews the history of the topical sensitizing agent squaric acid dibutylester and discusses the mechanism of action, the use in alopecia areata, and the efficacy and safety of this therapeutic agent.

Systemic immunomodulatory effects of topical dinitrochlorobenzene (DNCB) in rats. Activity of peripheral blood polymorphonuclear cells

Topical application of dinitrochlorobenzene (DNCB) is employed in the immunotherapy of skin diseases. Activation of T-cell mediated immune responses (Th1/type1) is the supposed mechanism of the clinical effect of DNCB, but there are no data concerning innate/inflammatory mechanisms. In this study, the effect of repeated topical DNCB application on peripheral blood polymorphonuclear (PMN) leukocytes has been examined in two rat strains which differ in the propensity to mount Th1/type1 or Th2/type2 responses. The dynamics of changes in PMN numbers and effector activities (respiratory burst, nitric oxide production and myeloperoxidase content), as well as in adhesion and TNF-α production following the rat skin sensitization with low (0.4%) and high (4%) DNCB doses were measured. Both priming and activation of PMNs were observed following skin sensitization with DNCB, with dose-dependent as well as time-dependent differences in some PMN activities. Obtained data might be relevant for understanding the immune mechanisms of topical DNCB therapy.

Association between IL17A/IL17RA Gene Polymorphisms and Susceptibility to Alopecia Areata in the Korean Population

Background

Alopecia areata is marked by autoimmune assault on the hair follicle resulting in hair loss. T helper 17 cell subset has important roles in protecting the host against extracellular pathogens, however, also promotes inflammatory pathology in autoimmune disease, and it expresses both interleukin (IL)-17A and IL-17F, which can signal via the IL-17 receptor A.

Objective

To investigate the significance of IL17A and IL17RA gene polymorphisms in the susceptibility to alopecia areata.

Methods

We conducted case-control association study of 238 alopecia areata patients and 270 matched healthy controls. Allele frequency of total 2 single nucleotide polymorphims in the IL17A gene and 4 single nucleotide polymorphims in the IL17RA gene were studied. The statistical analyses were performed according to onset age, the presence of familyhistory, clinical subtypes, and presence of nail involvement or body hair involvement.

Results

One single nucleotide polymorphim (rs879577) of IL17RA gene showed significant difference between alopecia areata patients group and controls group (p= 0.0288). One single nucleotide polymorphim (rs4819554) of IL17RA gene showed significant difference between the early onset and late onset alopecia areata (p=0.0421).

Conclusion

IL17RA gene polymorphism might contribute to the increased susceptibility to alopecia areata in Korean population, and IL17RA gene polymorphism may be associated with onset age.

Changes in distribution pattern of CD8 lymphocytes in the scalp in alopecia areata during treatment with diphencyprone

For many years, the role of T lymphocytes was hypothesized as being a major factor responsible for hair loss in alopecia areata (a.a.). While numerous lymphocytic populations were found around hair bulbs, changes in their distribution patterns in the skin during the course and recovery of the disease remain unknown. In the present study, distribution of CD8 lymphocytes in biopsies obtained from a.a. patients was measured before and during treatment using diphencyprone (DCP). Results show about a 600% increase in the number of CD8 lymphocytes under the epithelium and about a 250% increase around hair bulbs and other epidermal appendages during the study. These results were more significant in a group, which had good clinical response to the treatment. No change in the quantity of CD8 lymphocytes was observed around the blood vessels. Since CD8 lymphocytes are considered to be directly involved in the hair destruction process in a.a., their increased number around hair bulbs followed by hair regrowth may suggest that during DCP treatment they regain normal reactivity to hair antigens.

Effect of thioredoxin reductase 1 on glucocorticoid receptor activity in human outer root sheath cells

Alopecia areata (AA) is a common disease of patchy hair loss on the scalp that can progress to cover the entire scalp and eventually the entire body. Intralesional injection of corticosteroids is the first-line therapy for adult patients, however some patients do not respond to glucocorticoid treatment effectively. To delineate the molecular mechanism underlying glucocorticoid insensitivity, we examined the expression of glucocorticoid receptor (GR) and thioredoxin reductase 1 (TrxR1). In some case of glucocorticoid-resistant AA patients, the expression of TrxR1 was decreased in outer root sheath (ORS). We then investigated the effect of TrxR1 on GR activity using recombinant adenoviruses. Overexpression of TrxR1 markedly increased GR activity in ORS cells cultured in vitro. In addition, TrxR1 protected GR activity against H(2)O(2). Finally, TrxR1-enhanced GR activity was significantly inhibited by the overexpression of dominant negative form of Trx (Trx(C32S/C35S)). These results suggest that decreased TrxR1 may be one putative cause for glucocorticoid resistance in AA, through the impact on intracellular redox system.

The therapeutic use of topical contact sensitizers in benign dermatoses

Topical therapy using contact sensitizers has been practised since the 1960s to treat conditions associated with an altered immunological state. Dinitrochlorobenzene, squaric acid dibutyl ester and diphencyprone are most commonly employed in the therapy of alopecia areata and viral warts. Few dermatology departments in the U.K. provide such treatment. This systematic review discusses the various contact sensitizers used for topical immunotherapy, the methodology of treatment, factors influencing efficacy and likely adverse effects.

Alopecia areata update

Alopecia areata (AA) is a nonscarring hair loss condition. Among the many factors under investigation in the pathogenesis of AA, the main areas of concentration have been genetic constitution as well as nonspecific immune and organ-specific autoimmune reactions. Treatment with intralesional corticosteroid injections for localized patchy AA and topical immunotherapy for extensive AA have proven successful in the majority of patients, although all treatments are palliative and do not change the prognosis of the disease.

Successful treatment of alopecia areata-like hair loss with the contact sensitizer squaric acid dibutylester (SADBE) in C3H/HeJ mice

A type of hair loss closely resembling human alopecia areata has been described in C3H/HeJ mice. In order to test the assumed analogy with human alopecia areata, we investigated the efficacy of treatment with the contact allergen squaric acid dibutylester. In 12 C3H/HeJ mice with alopecia areata an allergic contact dermatitis was induced and elicited weekly on one side of the back by topical applications of squaric acid dibutylester. Overt hair regrowth was observed only on the treated side of the back in nine of 12 mice. Histopathologic examination revealed a change in the distribution of the inflammatory infiltrate from a dense perifollicular lymphocytic infiltrate around the mid and lower regions of hair follicles in untreated skin to a uniform presence in the upper dermis in treated skin. Immunohistomorphometric studies revealed that treatment with squaric acid dibutylester increased the CD4+/CD8+ ratio from approximately 1:2 in untreated alopecia areata to 1:1 in treated alopecia areata. Additional immunohistochemical investigations showed an aberrant expression of major histocompatibility complex class I, major histocompatibility complex class II and intercellular adhesion molecule 1 on keratinocytes of the mid and lower parts of hair follicles in untreated alopecia areata. In successfully treated skin ectopic major histocompatibility complex class I and II expression was clearly reduced, whereas intercellular adhesion molecule 1 expression showed only minor changes. In conclusion, alopecia areata-like hair loss in C3H/HeJ mice responded to treatment with the contact sensitizer squaric acid dibutylester analogous to human alopecia areata. Moreover, successful treatment changes the aberrant expression of major histocompatibility complex class I and II in a way similar to that observed in human alopecia areata. These observations support the concept that alopecia areata-like hair loss in C3H/HeJ mice can be utilized as an appropriate model for the study of human alopecia areata.

Efficacy of topical sensitizers in the treatment of alopecia areata

It has been more than 2 decades since the first report of the use of dinitrochlorobenzene to induce hair growth in 2 patients with alopecia areata. Other topical sensitizers, namely squaric acid dibutylester and diphenylcyclopropenone, have been used with variable success. This article reviews the efficacy and safety of the use of topical sensitizers in the treatment of alopecia areata.

Hair regrowth. Therapeutic agents

Today there are new classes of hair growth promotors with proven efficacy. This article reviews the current state of the art agents for treatment of two of the most common forms of hair loss encountered in clinical practice, androgenetic alopecia and alopecia areata. Current therapeutic strategies are based on recent advances in the understanding of disordered hair growth. Practical treatment protocols are presented.

An unusual case of alopecia areata of dental origin

The relationship between dental foci of infectious or mechanical nature and alopecia areata is analyzed through this case. There are many different causes for this dermatologic disease, and a dental origin seems to be very uncommon. Such a cause can only be confirmed a posteriori by a complete recovery of the patient after the dental cause is removed.

Dinitrochlorobenzene is genotoxic by sister chromatid exchange in human skin fibroblasts

Dinitrochlorobenzene (DNCB) is clinically efficacious in the therapy of alopecia areata, but its use was limited when it was found to be mutagenic in the Ames test. However, there has been renewed interest in the immunomodulatory benefits of topically applied dinitrochlorobenzene in patients with human immunodeficiency virus and systemic lupus erythematosus. The current study examines the genotoxicity of dinitrochlorobenzene in human skin fibroblasts using sister chromatid exchange. Dinitrochlorobenzene caused a significant increase in sister chromatid exchange at concentrations ranging from 2.5 to 10 microM. Thus, dinitrochlorobenzene is genotoxic in human skin fibroblasts at concentrations well below those used clinically. The potential for long-term toxicity from dinitrochlorobenzene will have to be weighed against the severity and prognosis of the diseases for which it is used.

Topical immunotherapy in alopecia areata. What, how, and why?

At present the induction and elicitation of an ACD with potent contact allergens such as DCP appear to be the most effective, but still not definitively curative, approach in treating extensive forms of AA. Experimental data suggest that cytokines and growth factors such as IL 1 beta are involved in the pathogenesis of AA as well as the therapeutic effect mediated by contact sensitizers. It seems reasonable to assume that factors inherent in the late phase of ACD modulate a T-cell mediated mechanism responsible for AA, thus inducing hair regrowth. Such counteracting activities are most likely mediated by proinflammatory cytokines such as TNF-alpha, IL-10, or TGF-beta 1. This hypothesis may oversimplify the underlying immunologic mechanisms, but the effectiveness of topical immunotherapy in AA would be compatible with this concept. This mode of treatment is, however, a rather rough approach and recurrences are possible. It is hoped that advances in basic science will eventually allow us to find a more specific mode of treatment.

Treatment of alopecia areata with squaric acid dibutylester

BACKGROUND

Among contact allergens that are frequently used in the treatment of alopecia areata (AA), squaric acid dibutylester (SADBE) stands out for its good tolerability and its mild side effects.

METHODS

One hundred and forty-four patients with AA of varying degrees were treated with SADBE. Of these, 71 had AA affecting less than 50% of the scalp, and 73 had a severe form, including 13 patients with alopecia totalis (AT) and two with alopecia universalis (AU). The patients were treated using both traditional and nontraditional methods.

RESULTS

In the less severe form, we obtained a 80% rate of regrowth, compared to the 49% of the more severe form including 13 cases of AT and the two of AU. The failure rate was higher for patients with the more severe form (29%) compared to a 7% rate only for patients with mild AA. We also observed four cases of initial regrowth on the side of the scalp opposite to the site of application ('castling phenomenon'). Among those patients who were treated with application of SADBE on the right side of the back, three displayed regrowth on the left side of the scalp, (i.e., on the opposite side) and in an area distant from the site of application; for two patients the regrowth began on the right side of the scalp and one of them also displayed growth of fine hairs in the right dorsal region, the site of application of the compound.

CONCLUSIONS

Our data further support the hypothesis of a systemic action of SADBE; however, further confirmation on a larger sample of cases is needed.

Alopecia areata in childhood

Aproximately 1% of the population will have had alopecia areata by the age of 50 and the peak incidence occurs in children and young adults. All body hair may be affected including lashes and brows. Alopecia areata is a systemic disease with frequent involvement of nails or eyes. Alopecia areata has been associated with atopic dermatitis, autoimmune disease, vitiligo, and endocrine disease. The pathogenesis is unclear. There is no excellent therapy for alopecia areata although many interventions are tried. Immunotherapy with diphenylcyprone is currently being optimistically evaluated. The harmful psychological effects of alopecia areata in children must be anticipated and prevented.