Spontaneous alopecia areata-like hair loss in one congenic and seven inbred laboratory mouse strains

Alopecia areata (AA) research has been hampered by the lack of suitable ani mal models for use in experimental procedures. AA-Like hair loss has been o bserved in several species, including dogs, cats, horses, cattle, and nonhu man primates; however, these examples are isolated cases in outbred species of large size, limiting their use in AA research. Inbred rodent strains ar e ideal research models. C3H/HeJ mice can develop spontaneous AA-Like hair loss and have previously been advanced as a suitable experimental model. Th e search for additional mouse strains with AA-like hair loss has continued, Nonscarring, inflammatory, spontaneously reversible hair loss has been obs erved in individual mice from several inbred mouse strains. Aside from C3H/ HeJ mice, an AA-like phenotype has been observed in the substrain C3H/HeJBi r, with an expression frequency of 5%, Up to 10% of individuals in an A/J m ouse colony have been confirmed to develop patchy AA-like hair loss. Isolat ed examples of AA have also been identified in C3H/HeN/J mice, C3H/OuJ mice , HRS/J+/hr heterozygous normal mice, CBA/CaHN-Btk(xid)/J mice, and BALB.2R -H2(h2)/Lil mice, each with a colony frequency of less than 1%. BALB.2R-H2( h2)/Lil mice may also have severe nail defects. AA is regarded as rare in n onhuman species; however, nonscarring inflammatory based alopecia has been identified in several mouse strains. These examples may represent different subtypes of the heterogeneous AA phenotype, Pathologic and genetic analysi s of different AA affected mouse strains may contribute to understanding AA pathogenesis and elucidating susceptibility genes.