Lichen planus and lichenoid dermatoses: Conventional and emerging therapeutic strategies.

Having reviewed the diverse clinical subtypes of lichenoid disease and the postulated molecular basis thereof in the first article in this 2-part continuing medical education series, we discuss herein the existing and emerging treatment strategies in the most common clinical forms of lichenoid inflammation and provide an overview of their pharmacodynamics and evidence base. The scope of this review is not to exhaustively discuss treatment modalities for all lichenoid variants discussed in the previous article of this series. Instead, the focus will be on frequently encountered subtypes of lichen planus and on linking mechanisms of disease with mechanisms of drug action. Future directions and potential avenues for translational research will also be discussed.

Lichen planus and lichenoid dermatoses: Clinical overview and molecular basis.

Deriving from the Greek word λειχήν for "tree moss" and the Latin word planus for "planar," lichen planus is a relatively uncommon and heterogeneous cutaneous disorder that typically develops in middle-aged adults. Despite the significant clinical burden associated with the disorder, little well-conducted molecular research has been undertaken, possibly because of heterogeneity impeding consistent and confident phenotyping. The multiple variants of lichenoid disease bear overlapping clinical and pathologic features despite manifesting as distinct clinical disorders. The first article in this 2-part continuing medical education series provides a comprehensive overview of the clinical and pathologic characteristics of cutaneous lichenoid dermatoses and links these manifestations to recent advances in our understanding of the underlying pathobiology of such diseases.

Permanent alopecia in patients with breast cancer after taxane chemotherapy and adjuvant hormonal therapy: Clinicopathologic findings in a cohort of 10 patients.

BACKGROUND: Anagen effluvium with reversible scalp alopecia is a known side effect of chemotherapy. However, there are an increasing number of reports in the literature documenting permanent alopecia in patients treated with taxanes. OBJECTIVE: We sought to describe the clinicopathologic features in breast cancer patients who underwent treatment with taxanes and adjuvant hormonal chemotherapy. METHODS: We reviewed the clinical and histopathologic information of a cohort of 10 patients treated with taxanes and adjuvant hormonal chemotherapy. RESULTS: We have observed 3 types of clinical patterns of alopecia (types A, B, and C), and have validated the histopathologic features showing alopecia areata-like and female pattern hair loss. LIMITATIONS: The study was based on a small sample size and retrospective retrieval of clinical information and histopathologic review of posttreatment slides. CONCLUSIONS: We hypothesize a clinicopathologic model of hair follicle cycle disruption in response to the chemoinflammatory and hormonal insults to the hair follicles resulting in permanent alopecia. Clinicopathologic correlation is paramount to the understanding of the morphobiologic pathways in chemotherapy-induced alopecia caused by taxanes and adjuvant hormonal treatment.

Frontal fibrosing alopecia: reflections and hypotheses on aetiology and pathogenesis.

Since first described by Kossard in 1994, frontal fibrosing alopecia (FFA) has been something of an enigma. The clinical heterogeneity of FFA, its apparent rarity and investigators' suboptimal access to phenotypically consistent patient cohorts may all have had a negative impact on delineating disease pathogenesis. Moreover, there is a relative paucity of epidemiological, interventional and basic research studies, and there have been no advances in translational therapeutics, unlike for other inflammatory dermatoses, such as alopecia areata (AA). Dermatologists anecdotally describe an increasing incidence in FFA over the last decade, which has led to the notion that the disorder may be induced by unknown environmental triggers. On the other hand, segregation of FFA in some families lends support to an unexplored genetic element implicated in disease pathogenesis. We herein review what is known about the pathobiology of FFA and formulate working hypotheses to advance insight into this intriguing hair disorder.

Hair Follicle Miniaturization in a Woolly Hair Nevus: A Novel "Root" Perspective for a Mosaic Hair Disorder.

Woolly hair nevus is a mosaic disorder characterized by unruly, tightly curled hair in a circumscribed area of the scalp. This condition may be associated with epidermal nevi. We describe an 11-year-old boy who initially presented with multiple patches of woolly hair and with epidermal nevi on his left cheek and back. He had no nail, teeth, eye, or cardiac abnormalities. Analysis of plucked hairs from patches of woolly hair showed twisting of the hair shaft and an abnormal hair cuticle. Histopathology of a woolly hair patch showed diffuse hair follicle miniaturization with increased vellus hairs.

The current state of play in the histopathologic assessment of alopecia: two for one or one for two?

The histopathologic assessment of a scalp biopsy for alopecia relies largely on the quality of the specimen provided for evaluation. There are a number of different protocols in the literature which have been proposed over the years, but no consensus has yet been reached as to the appropriate number of biopsies to be taken, or to which sectioning technique is the gold standard for achieving the best diagnostic yield. We herein review the pros and cons of the various protocols and share the experience with our St John's protocol.

Frontal fibrosing alopecia and lupus overlap in a man: guilt by association?

Frontal fibrosing alopecia (FFA) is a scarring alopecia, now an accepted subset variant of lichen planopilaris (LPP). Its occurrence in males is rare, with only nine cases reported to date. We describe a case of FFA in a male in association with lupus erythematosus. Multiple biopsies from the scalp, eyebrow and arm showed features consistent with LPP, in keeping with the clinical presentation of FFA. Direct immunofluorescence studies showed a positive lupus band test. Further serological investigation confirmed the presence of antinuclear, anticardiolipin and lupus anticoagulant antibodies. Whilst the findings of lupus erythematosus may be coincidental or a forme fruste of the disease occurring in association with FFA, it is feasible that lupus and LPP may occur as an overlap syndrome. This case underscores the importance of multiple biopsies and the role of direct immunofluorescence in disclosing more than one pathology in the follow-up of patients with scarring alopecia.

Expanding the spectrum of frontal fibrosing alopecia: a unifying concept.

BACKGROUND: In frontal fibrosing alopecia (FFA), scalp alopecia dominates the clinical picture. However, eyebrow loss and hair loss in other body sites may also occur; this has been documented clinically, but rarely histopathologically. We describe the clinicopathological findings of 13 cases of FFA, with histopathologic data from the scalp, eyebrow, and body hair. METHODS: Thirteen patients with a diagnosis of FFA, seen between 2006 and 2008, were included. Scalp biopsies were performed in all patients for histology and direct immunofluorescence (DIF). Biopsy specimens for histology were taken from the eyebrow in 6 patients and from the upper limb in 5 patients. RESULTS: All 13 patients were female, 11 of whom were postmenopausal. The median age at onset of alopecia was 57 years. Clinical examination revealed a band of frontal hairline recession in all patients. Eyebrow loss was present clinically in all patients, with loss of body hair in 10 of 13. Histopathologic examination of the scalp, eyebrow, and upper limb skin biopsy specimens showed similar features, including a marked reduction in the number of hair follicles and a perifollicular lymphoid cell infiltrate with perifollicular fibrosis. Direct immunofluorescence was negative in all cases. LIMITATIONS: Not all patients consented to biopsies of the eyebrows or upper limbs. CONCLUSION: Eyebrow and peripheral body hair loss is not uncommon in FFA-a finding that is likely underreported. We have demonstrated that alopecia of the upper limbs in FFA is indeed common and, histopathologically, shows features of lichen planopilaris and scarring, similar to findings in the scalp and eyebrows. Consequently, the process of lichen planopilaris with scarring alopecia is generalized rather than localized only to the frontal scalp and eyebrows.

Trichohyalin is a potential major autoantigen in human alopecia areata.

Several lines of evidence support an autoimmune basis for alopecia areata (AA), a common putative autoimmune hair loss disorder. However, definitive support is lacking largely because the identity of hair follicle (HF) autoantigen(s) involved in its pathogenesis remains unknown. Here, we isolated AA-reactive HF-specific antigens from normal human scalp anagen HF extracts by immunoprecipitation using serum antibodies from 10 AA patients. Samples were analyzed by LC-MALDI-TOF/TOF mass spectrometry, which indicated strong reactivity to the hair growth phase-specific structural protein trichohyalin in all AA sera. Keratin 16 (K16) was also identified as another potential AA-relevant target HF antigen. Double immunofluorescence studies using AA (and control sera) together with a monoclonal antibody to trichohyalin revealed that AA sera contained immunoreactivity that colocalized with trichohyalin in the growth phase-specific inner root sheath of HF. Furthermore, a partial colocalization of AA serum reactivity with anti-K16 antibody was observed in the outer root sheath of the HF. In summary, this study supports the involvement of an immune response to anagen-specific HFs antigens in AA and specifically suggests that an immune response to trichohyalin and K16 may have a role in the pathogenesis of the enigmatic disorder.