Page 1074 - Problem-Based Feline Medicine

1066 PART 13 CAT WITH SKIN PROBLEMS

biopsy results were suggestive of this. There are too The most common locations affected include the head,
few case reports to make any prescriptive treatment neck and trunk.
recommendations.
The affected skin appears otherwise normal. There is
The prognosis is therefore poor. no inflammation evident grossly and pruritus is not a
feature.
ALOPECIA AREATA Chronic lesions may develop hyperpigmentation.

Classical signs
Diagnosis
● Gradual onset of focal or multi-focal areas
of alopecia. A tentative diagnosis is based on the history of grad-
● Non-pruritic. ual hair loss, and the clinical signs of well-demarcated
● The skin is non-inflamed and appears alopecia, without any significant inflammation.
otherwise normal. Biopsy of early skin lesions reveals a mononuclear
● Long-standing lesions may become inflammatory cell infiltrate both surrounding and
hyperpigmented. within the hair follicles.

At later stages, the inflammation is largely absent.
Pathogenesis Catagen and telogen hair follicles predominate at this time-
In humans, an immune-mediated basis is suggested point. Follicular atrophy is also evident. In some biopsy
by: specimens, there is complete absence of follicles.
● Accumulations of lymphoid cells around hair bulbs
during the active phase of the disease.
Treatment
● Occasional association of alopecia areata with other
immune-mediated diseases. There may be spontaneous re-growth of hair in some
● Increased incidence of various autoantibodies in cats after a variable period of time.
alopecia areata.
Glucocorticoids have been employed by a variety of
● Decreased numbers of circulating T-cells.
routes. However, no data are available to support the
● Deposition of C3 or IgG or IgM at the basement
use of glucocorticoid medication in the treatment of
membrane zone of hair follicles.
this disease.
Clinical signs
Rare condition in cats.

Typically there are single or multiple sites of alopecia,
which are generally well-demarcated and usually non-
symmetrical. Hair loss is gradual.

RECOMMENDED READING
Baker KP, Thomsett LR. Heritable defects. In: Canine and Feline Dermatology. Blackwell Scientific Publications,
1990, pp. 63–75.
Mooney CT. Unusual endocrine disorders in the cat. In Practice 1998; 20(7): 345–349.
Moriello K, Mason I. Alopecia in cats. In: Handbook of Small Animal Dermatology. Pergamon, 1995, pp. 163–168.
Scott DW, Miller WH, Griffen CE. Acquired alopecias. Congenital and hereditary defects. Psychogenic skin dis-
eases. In: Muller and Kirk’s Small Animal Dermatology, 5th edn. Philadelphia, PA, W.B. Saunders, 1995,
pp. 720–735, 736–805, 845–858.