Page 1070 - Problem-Based Feline Medicine

1062 PART 13 CAT WITH SKIN PROBLEMS

with the quality of life, drug withdrawal may not be Both autosomal dominant and recessive inheritance
appropriate, depending on the underlying condition for patterns have been reported in human patients with a
which the drug was prescribed. combination of pili torti and varying degrees of hearing
loss. Other ectodermal defects are also documented in
If drug hypersensitivity is suspected, see page 1034, The
affected individuals.
Cat With Miliary Dermatitis, for details of diagnosis.
A localized form of disease may occur secondary to
follicular inflammation.
Differential diagnosis
Clinical signs
Alopecia can be caused by all the conditions listed in
this chapter. However, the major differentials would be Appears as generalized alopecia in young kittens
diabetes mellitus, hyperadrenocorticism and hyper- affecting secondary but not primary hairs. Most affected
thyroidism. Dietary causes should also be excluded. kittens have marked alopecia by 10 days of age.
Periocular and pedal involvement are commonly pres-
ent. Affected kittens thus commonly present with pedal
Treatment
dermatitis and paronychia.
If appropriate, the offending medication should be
Affected kittens usually die or are euthanized.
withdrawn.
Treat any secondary infection, and crusted or ulcerated Diagnosis
areas with appropriate antimicrobial agents and symp-
A tentative diagnosis is based on the history and clin-
tomatic therapy as indicated.
ical signs.
A definitive diagnosis is possible with skin biopsy of
PILI TORTI
affected areas and examination of affected secondary
hairs.
Classical signs
Electron microscopy of these secondary hairs can pro-
● Generalized alopecia by 10 days of age.
vide additional diagnostic information.
● Pedal dermatitis and nail-bed infections.
● Affected kittens normally die or require Treatment
euthanasia.
No treatment is available.
Pathogenesis
TELOGEN DEFLUXION
The pathogenesis is unknown.
Curvature of the hair follicle results in flattening and Classical signs
rotation of hair shafts.
● Alopecia affecting any or most parts of the
This leads to a generalized alopecia in young kittens, body.
with virtually all secondary hairs becoming involved. ● Gradual shedding of telogen hairs, usually
Primary hairs are not usually affected. 1–3 months after a stressful event.
● Skin is clinically normal.
Pili torti is usually an inherited disorder in man, with
affected individuals having additional systemic and
skin abnormalities. Clinical signs
Acquired syndromes similar to pili torti are addition- Telogen defluxion normally results from the premature
ally reported following various physical and chemical cessation of hair growth in anagen follicles because of
insults in man. a stressful factor, e.g. pregnancy, internal disease, etc.