24 Alopecia X in a Pomeranian
Symmetrical, truncal, non-inflammatory alopecia can occur for a number of different reasons, including follicular dysplasias and endocrinopathies. The most common endocrinopathies resulting in these symptoms are hypothyroidism and hyperadrenocorticism. There is a form of alopecia that occurs in plush-coated Nordic breeds characterized by bilaterally symmetrical, non-inflammatory alopecia with hyperpigmentation. The exact aetiology is not known and the condition has been designated ‘alopecia X’. This case report describes a case of alopecia X in a Pomeranian.
The symptoms of symmetrical, non-inflammatory, truncal alopecia were supportive of a hair growth cycle disorder due to an endocrinopathy, although the differential diagnosis would include other causes of non-pruritic hair loss, including:
As with any case of alopecia, skin scrapes should be performed to rule out demodicosis. Routine haematological and biochemical examinations and further tests for hyperadrenocorticism and hypothyroidism were also indicated. In addition to a standard ACTH stimulation test measuring pre- and post-ACTH cortisol concentrations, the same test, measuring pre- and post-17-hydroxy-progesterone concentrations, has been used as an indicator of adrenal dysfunction. Post-ACTH 17-hydroxy-progesterone concentrations are frequently elevated in cases of alopecia X. Histopathological examination is unlikely to give a definitive diagnosis in a case of alopecia due to an endocrinopathy but would be helpful in ruling out other causes of hair loss.