Page 1062 - Problem-Based Feline Medicine

1054 PART 13 CAT WITH SKIN PROBLEMS

contined

Affected skin may become thickened and hyperpigmented. An environmental stressor may be
identified in the history.
INFLAMMATION/INFECTION:
Bacterial:
● Staphylococcal dermatitis* (p 1064)
Primary staphylococcal dermatitis is uncommon in cats, and an underlying disease process should
be suspected. Typically there is erythema, scale and crustiness. Hair follicles are commonly
involved. Papules are common, but rarely is pus present.
Fungal:

● Dermatophytosis** (p 1060)
More common in young kittens. Erythematous plaques, alopecia and scale. Lesions may progress
to larger gray areas of alopecia and hyperkeratosis.
Parasitic:
● Demodicosis* (p 1061)
Localized or generalized alopecia of face and trunk. Periocular and nasal involvement are most
common. Lesions have erythema and scale. Most cases are non-pruritic.
Immune:
● Alopecia areata (p 1066)
Focal or multi-focal alopecia which is gradual in onset, and not symmetrical. The skin is not
inflamed and there is no pruritus. Hyperpigmentation may occur chronically. Rare.
Toxic/drug
● Drug reaction* (p 1061)
Usually associated with immunosuppressive or anti-neoplastic agents. Alopecia is most common
on the body trunk, but can affect other sites. Secondary infection is often present. Glucocorticoids
may produce cutaneous signs of hyperadrenocorticism.

Some causes of alopecia are genetically programmed.
INTRODUCTION Acquired cases may arise because of hormonal influ-
ences that interfere with hair growth, or as a result
of folliculitis. Hairs may also be lost as a direct result
MECHANISM?
of self-trauma for a variety of reasons.
● Failure to grow hair may be a life-long problem,
Alopecia is the loss or absence of hairs from areas of
as occurs in congenital or genetically programmed
the cat’s body that would normally possess hairs.
alopecias.
● This phenomenon can result either from a failure to
grow hair or as a consequence of the abnormal Abnormal hair loss has a wide variety of causes, and is
loss of hairs. normally divided clinically into those cases which are