How close are we to solving the puzzle? Review of the Alopecia Areata Research Workshop David Norris

The C3H/HeJ mouse and DEBR rat models for alopecia areata: review of preclinical drug screening approaches and results

The C3H/HeJ inbred mouse strain and the Dundee Experimental Bald Rat (DEBR) strain spontaneously develop adult onset alopecia areata (AA), a cell-mediated disease directed against actively growing hair follicles. The low frequency of AA and the inability to predict the stage of AA as it evolves in the naturally occuring C3H/HeJ model of AA can be converted into a highly predictable system by grafting full thickness skin from AA-affected mice to normal haired mice of the same strain. The rat DEBR model develops spontaneous AA at a higher frequency than in the mouse model but they are more expensive to use in drug studies owing to their larger size. Regardless of the shortcomings of either model, these rodent models can be used succesfully to screen novel or approved drugs for efficacy to treat human AA. As the pathogenesis of AA follows the canonical lymphocytic co-stimulatory cascade in the mouse AA model, it can be used to screen compounds potentially useful to treat a variety of cell-mediated diseases. Efficacy of various agents can easily be screened by simply observing the presence, rate, and cosmetic acceptability of hair regrowth. More sophisticated assays can refine how the drugs induce hair regrowth and evaluate the underlying pathogenesis of AA. Some drugs commonly used to treat human AA patients work equally as well in both rodent models validating their usefulness as models for drug efficacy and safety for humanAA.

Alopecia areata masquerading as frontal fibrosing alopecia

SUMMARY Postmenopausal women with frontal recession may represent a diagnostic challenge, as frontal fibrosing alopecia and alopecia areata may be clinically difficult to distinguish. A 53-year-old postmenopausal woman presented with a progressive fronto-temporal marginal alopecia with sparing of her eyebrows. Scalp biopsy of the affected frontal hairline revealed peribulbar lymphocytic inflammation, but no evidence of lichenoid inflammation, perifollicular fibrosis or scarring. Whereas the pathology strongly favoured alopecia areata, the clinical features overlapped with frontal fibrosing alopecia, a variant of lichen planopilaris targeting the frontal scalp. This paper presents an atypical clinical presentation of alopecia areata, which may be mistaken for frontal fibrosing alopecia.