The hair follicle-psoriasis axis: Shared regulatory mechanisms and therapeutic targets

It has long been known that there is a special affinity of psoriasis for the scalp: Here, it occurs most frequently, lesions terminate sharply in frontal skin beyond the hair line and are difficult to treat. Yet, surprisingly, scalp psoriasis only rarely causes alopecia, even though the pilosebaceous unit clearly is affected. Here, we systematically explore the peculiar, insufficiently investigated connection between psoriasis and growing (anagen) terminal scalp hair follicles (HFs), with emphasis on shared regulatory mechanism and therapeutic targets. Interestingly, several drugs and stressors that can trigger/aggravate psoriasis can inhibit hair growth (e.g. beta-blockers, chloroquine, carbamazepine, interferon-alpha, perceived stress). Instead, several anti-psoriatic agents can stimulate hair growth (e.g. cyclosporine, glucocorticoids, dithranol, UV irradiation), while skin/HF trauma (Köbner phenomenon/depilation) favours the development of psoriatic lesions and induces anagen in "quiescent" (telogen) HFs. On this basis, we propose two interconnected working models: (a) the existence of a bidirectional "hair follicle-psoriasis axis," along which keratinocytes of anagen scalp HFs secrete signals that favour the development and maintenance of psoriatic scalp lesions and respond to signals from these lesions, and (b) that anagen induction and psoriatic lesions share molecular "switch-on" mechanisms, which invite pharmacological targeting, once identified. Therefore, we advocate a novel, cross-fertilizing and integrative approach to psoriasis and hair research that systematically characterizes the "HF-psoriasis axis," focused on identification and therapeutic targeting of selected, shared signalling pathways in the future management of both, psoriasis and hair growth disorders.

Cutaneous Lupus Erythematosus Limited to the Site of a Laceration

Background:

Cutaneous lupus erythematosus is known to occur at sites of trauma or inflammation of the skin, including sites of tattoo, frostbite, herpes zoster scar, burn scar, and implantation by windshield glass.

Objective:

We report a 32-year-old white man who developed cutaneous lupus erythematosus at the site of a laceration. The diagnosis was confirmed by histologic and immunofluorescence examination. The patient responded to intralesional corticosteroid and hydroxychloroquine therapy.

Conclusion:

Lupus erythematosus may be induced by trauma.

The role of inflammation in sarcoma

Sarcomas encompass a heterogenous group of tumors with diverse pathologically and clinically overlapping features. It is a rarely curable disease, and their management requires a multidisciplinary team approach. Chronic inflammation has emerged as one of the hallmarks of tumors including sarcomas. Classical inflammation-associated sarcomas comprise the inflammatory malignant fibrous histiocytoma and Kaposi sarcoma. The identification of specific chromosomal translocations and important intracellular signaling pathways such as Ras/Raf/MAPK, insulin-like growth factor, PI3K/AKT/mTOR, sonic hedgehog and Notch together with the increasing knowledge of angiogenesis has led to development of targeted therapies that aim to interrupt these pathways. Innovative agents like oncolytic viruses opened the way to design new therapeutic options with encouraging findings. Preclinical evidence also highlights the therapeutic potential of anti-inflammatory nutraceuticals as they can inhibit multiple pathways while being less toxic. This chapter gives an overview of actual therapeutic standards, newest evidence-based studies and exciting options for targeted therapies in sarcomas.

Vitiligo koebnerized by behçet disease genital ulceration

A 50-year-old man was diagnosed with Behçet disease (BD) on the basis of an 8-year history of episodes of recurrent oral aphthous ulcers, papulopustular lesions on physical examination, and a positive pathergy test. Two years prior to diagnosis of BD, vitiligo had also been diagnosed on the basis of hypopigmented lesions on the scrotum following genital ulceration. To our knowledge, this is the first case of incidental coexistence of BD and vitiligo, and, furthermore, the first case of koebnerization of genital ulceration of BD.

Threading warts: a beauty parlor dermatosis

Threading is a common beauty parlor procedure usually performed to shape the eyebrows and remove unwanted facial hair for cosmetic reasons. Appearance of warts at the site of threading is an unusual phenomenon. We report two such cases, first as koebnerization from the initial lesion elsewhere on the patient's body and second, possibly from the infected material at the beauty parlor. We emphasize the importance of identification of this condition and discuss its dermatological and cosmetological perspectives.

Winnie the Pooh and psoriasis too: an isomorphic response of guttate psoriasis in a tattoo

Since Koebner's first observance of the isomorphic response of psoriasis in a tattoo in 1872, a paucity of written reports has appeared in the literature describing this phenomenon, although it appears to be common knowledge among dermatologists. We report a strep-induced guttate psoriasis isomorphic response in a Winnie the Pooh tattoo in a 19-year-old.

Vitiligo koebnerized by eyebrow plucking by threading

Koebnerization is a well-known phenomenon in diseases like vitiligo and psoriasis. Eyebrow plucking is a common procedure, which induces some trauma. This is a report of a woman with vitiligo whose vitiligo spread to the eyebrow area after eyebrow plucking by threading in a beauty parlour. This is an example of an unusual koebnerization of vitiligo by a very common cosmetic procedure.

Pemphigus foliaceus masquerading as postoperative wound infection: report of a case and review of the Koebner and related phenomenon following surgical procedures

BACKGROUND

The Koebner phenomenon, also known as the isomorphic response, is the development of preexisting skin disease following trauma to uninvolved skin. Various cutaneous disorders have been described to arise at surgical wounds and scars. Moreover, dermatologic procedures, such as cold-steel and laser surgery, can evoke koebnerization.

OBJECTIVE

To describe a case of pemphigus foliaceus arising in postoperative wounds and to present a review of dermatologic disorders triggered by surgical procedures.

METHODS

We report a case of pemphigus foliaceus initially presenting at sites of Mohs' micrographic surgery, shave biopsy, and cryotherapy and, subsequently, at a nonsurgical site. We reviewed the English literature in MEDLINE from November 1955 to April 2004 for reports of Koebner and related phenomenon following surgical procedures.

RESULTS

To our knowledge, this is the first reported case of pemphigus foliaceus erupting at surgical and cryotherapy wounds. The clinical appearance can mimic wound infection. In addition to inducing preexisting disease, cutaneous procedures can also trigger the onset of new disease, which can either be limited only to the surgical site or subsequently become generalized.

CONCLUSION

Postoperative Koebner or related responses should be included in the differential diagnosis of poorly healing surgical wounds. Skin biopsies for histopathology and immunologic studies may be necessary for definitive diagnosis and optimal management.

Update on the management of cutaneous lupus erythematosus

This paper reviews the latest treatments for cutaneous lupus erythematosus. It focuses on evidence-based guidance for the management of cutaneous lupus erythematosus, with identification of the strength of evidence available at this time. In addition, I have briefly reviewed the epidemiological aspects, diagnosis and evaluation of patients with cutaneous lupus erythematosus. This review reflects data available from the Cochrane Library, Medline, literature searches, and the experience of the author managing patients with cutaneous lupus erythematosus for over 25 years.

Increased E-selectin, IL-8 and IL-10 gene expression in human skin after minimal trauma

While clinical observations suggest that trauma to the skin plays a critical role in the induction of skin lesions in some skin diseases, the mechanism by which these lesions are induced is not known. We have postulated that minor trauma to the skin may lead to the expression of critical adhesion molecules on epidermal endothelial cells (E-selectin) and pro-inflammatory cytokines, which would predispose these areas to the development of skin lesions. In order to test this hypothesis normal inner arm skin of 11 normal subjects was gently rubbed with a pencil eraser for 2 min. Four hours after rubbing, skin biopsies were obtained from the rubbed site and from adjacent normal, unrubbed inner arm skin. Expression of E-selectin, intercellular adhesion molecules (ICAM-1) and the mRNA of selected cytokines was studied utilizing real time polymerase chain reactions. Biopsies were also examined for the presence of an inflammatory infiltrate and for the presence of E-selectin and ICAM-1. No clinical or histologic changes were seen in the skin expression/unrubbed skin expression = 9.0; (median ratio rubbed skin expression/unrubbed skin expression range 0.9-161.0), ICAM-1 (median rubbed skin expression/unrubbed skin expression = 3.2; range 0.9-19.8), IL-8 (median rubbed skin expression/unrubbed skin expression = 6.6; range 2.6-57.3) and IL-10 (median rubbed skin expression/unrubbed skin expression = 13.1; range 2.4-29.0) was noted. Immunohistochemistry revealed the presence of E-selectin in the dermal blood vessels in three of four subjects 4 h after rubbing but not in the unrubbed skin. Changes in ICAM -1 or HLA-DR deposits were seen in the rubbed compared with the unrubbed skin. These findings demonstrated that minor trauma to skin may induce expression of E-selectin, ICAM-1 and IL-8, which may make the skin a more permissive site for the development of inflammatory reactions. These findings may play an important role in the development of skin lesions in areas of minor trauma.