Page 1476 - Clinical Small Animal Internal Medicine

1414 Section 12 Skin and Ear Diseases

Table 160.1 Possible factors for triggering urticaria
VetBooks.ir Trigger Remarks
and angioedema in dogs and cats

Foods
Drugs Penicillin, ampicillin, cephalexin,
tetracycline, vitamin K, propylthiouracil,
amitraz, ivermectin, moxidectin,
vincristine, azathioprine
Vaccines Panleukopenia, leptospirosis, distemper‐
hepatitis, rabies, feline leukemia
Insect bites/stings Bee, hornet, mosquito, black fly, spider, ant
Atopy Pollen, mold, dust mite
Blood transfusions
Plants Nettle, buttercup
Intestinal parasites Ascarids, hookworms, tapeworms
Infections Staphylococcal pyoderma, canine
distemper
Sunlight
Excessive heat and
cold Figure 160.2 Three‐year‐old female spayed mastiff with facial
angioedema.
Estrus
Dermatographism
Psychogenic however, this may be challenging and not always
factors achievable. In persistent or severe cases, symptomatic
Vasculitis therapy is necessary. Epinephrine (0.1–0.5 mL of a 1:1000
solution SC or IM) combined with injectable glucocorti-
coids and/or antihistamines may be needed for severe
cases. For persistent cases of urticaria, oral glucocorti-
coids (e.g., prednisone/prednisolone at 2 mg/kg/day PO)
as well as oral antihistamines (e.g diphenhydramine,
hydroxyzine, each at 2.0 mg/kg twice daily) are given. In
mild cases, antihistamines are typically used as sole
therapy.

Prognosis
If the cause of the disease can be identified and exposure
eliminated, the prognosis is considered good.

Allergic Contact Dermatitis

Etiology/Pathophysiology
Allergic contact dermatitis is a type IV hypersensitivity
reaction associated with a cell‐mediated allergic response
to haptens, which are small reactive lipid‐soluble mole-
cules. Although an overlap between irritant and allergic
contact dermatitis has been reported in regard to
cytokine profile and inflammatory cell activation, aller-
Figure 160.1 Five‐year‐old male neutered mixed‐breed dog with gen‐specific CD4+ T cells (CCR10+) and some
multifocal wheals on lateral trunk and hind legs. chemokines (e.g., IP‐10) seem to be expressed exclusively