Non pruritic Alopecia 1

Question 1

What is alopecia?

Answer 1

Loss or absence of hair

Question 2

How can alopecia present?

Answer 2

As partial or complete alopecia

Localised, generalised, symmetrical or multifocal

As a primary or secondary lesion

Question 3

How is alopecia classified? What does each mean?

and causes

Answer 3

Spontaneous or Self induced

Spontaneous = no animal involvement
Various causes

Self induced = Animal removes hair
Causes = Pruritus (ectoparasities, allergic skin disease)
Psychogenic (behavioural, internal pain/inflammation)

This lecture only talking about spontaneous causes

Question 4

How to we know for sure alopecia isn’t caused by pruritus at onset?

Answer 4

1. Cutaneous signs of pruritus = feel of coat or saliva staining
2. Clinical testing = Conchiformibius sp. on cytology = commensal in mouth
   Trichograms – showing broken hair shafts in pruritic animals, but also showing exclamation point hairs in alopecia areata and marked telogenisation in endocrine disease

Question 5

What is the approach to alopecia diagnosis?

Answer 5

History
Physical examination
Differentiate spontaneous vs self-induced AGAIN- important so don’t go wrong
Differentiate inflammatory vs non-inflammatory
List differential diagnoses
Make diagnostic plan

Question 6

When approaching a alopecia case, what do we need to gather from our history?

Answer 6

1. Signalment: breed predisposition Is important!
2. Age of onset, duration, seasonality
3. Pruritus = inflammatory
4. Contagion? Dermatophytosis
5. History of travel: Leishmaniasis?
6. Signs of systemic disease?
7. Drug history: injection alopecia? Steroids causing this?!

Question 7

What alopecia diseases are common in:
adults
Pups
Older dogs

Answer 7

Puppies	
-Demodicosis
-Dermatophytosis
-Growth hormone deficiency (GSD)
Adults
-Immune mediated disease (e.g. sebaceous adenitis)
Older dogs
-Hypothyroidism
-Hyperadrenocorticism
-Neoplasia (e.g. epitheliotropic lymphoma
-Adult-onset demodicosis

Question 8

On the physical exam of a dog with alopecia what are you assessing?

Answer 8

1. Character and distribution of the lesion
2. Character of the alopecia: partial/ complete. Regular/ irregular patches
3. Distribution: asymmetrical vs symmetrical. Focal/ multifocal vs generalsied, other skin lesions, erythema, hyperpigmentation, scaling, comedones, skin atrophy

Question 9

Cushings, vs hyperthyroid. Pruritic?

What is you see Calcinosis cutis

Answer 9

Cushings = hyperadrenocortisicm hardly ever pruritic even if secondary bacterial infection!
Hyperthyroid = always

Calcinosis cutis = going to be a steroid problem