Pruritis and Alopecia

Question 1

Axons that mediate the ‘sensation’ of pain or itch are _______ ______.

Answer 1

Unmyelinated axons [C fibers]

Question 2

Cell bodies for itch are located in the ________ ________ _______ of spinal nerves & the _______ ________ of CN V for the face.

Answer 2

Dorsal root ganglia, Trigeminal ganglion

Question 3

In the white matter of the dorsal horn, there are bundles of cords called the ________ ______ that receive incoming action potentials (for pain) and transmit them to the brain.

Answer 3

Spinothalamic tract

Question 4

The brain’s itch processing centers have been preliminarily identified as the ________ ________ _______.

Answer 4

Primary somatosensory cortex

Question 5

Itch neurons intersect or intercommunicate with other neurons, esp. those that mediate _______.

Answer 5

Pain

Question 6

The mediator of pruritis is _______; released by mast cells but we know there are other mediators involved as well.

Answer 6

Histamine

Question 7

The 3 major causes of pruritis in a dog are?

Answer 7

1. Allergies, 2. Ectoparasites, 3. Infections

Question 8

The 4 major allergies that cause pruritis?

Answer 8

1. Flea allergy
2. Atopic dermatitis
3. Cutaneous adverse food reaction
4. Insect bite hypersensitivity/contact dermatitis

Question 9

The 5 major ectoparasites that cause pruritis in a dog are what?

Answer 9

1. Sarcoptes
2. Demodex (although pyoderma is what triggers the itch in dogs)
3. Cheyletiella [walking dandruff]
4. Lice
5. Chiggers

Question 10

The 3 major infections that cause pruritis in a dog is?

Answer 10

1. Pyoderma, 2. Yeast (mallazessia) and 3. Dermatophytes (Trichophyton and Microsporum)

Question 11

The two common locations on the body effected by Sarcoptic mange are?

Answer 11

1. Elbows and 2. Ears (they will have a positive pinna-pedal reflex)

Question 12

Are flea allergy, atopy, and insect allergy considered seasonal?

Answer 12

Yes, except flea allergy and atopy which can occur year round in states without seasons like FL and CA.

Question 13

T/F: When grading pruritis on a scale of 1-10, 10 would be considered the absolute worst.

Answer 13

True [this type of pruritis is the kind that wakes the owner up in the middle of the night, and is digging on him/herself in the exam room, despite the fact that endogenous cortisol is typically released from stress at the vet, this is the time the pet should be least itchy, these grade 10 dogs will be itchy no matter what!]

Question 14

The top 3 causes of the most severe pruritis 10/10 are:

Answer 14

1. Scabies
2. Flea allergy
3. Food allergy

Question 15

If pruritis came before the lesions you can expect it might be caused by which 2 things?

Answer 15

1. Allergies

2. Scabies

Question 16

If the lesion showed up before the pruritis, you can expect it might be from which 3 things?

Answer 16

1. Demodicosis
2. Dermatophytes
3. Pyoderma

Question 17

What are the 3 different types of skin lesions in cats?

Answer 17

1. Bilaterally symmetrical hair loss with normal skin: non-inflammatory
2. Miliary dermatitis
3. Eosinophilic granuloma complex

Question 18

What are 3 different inflammatory diseases that can effect the hair follicle?

Answer 18

1. Folliculitis/pyoderma
2. Ringworm
3. Demodex

Question 19

What are 2 different non-inflammatory diseases that can effect the hair follicle?

Answer 19

1. Endocrine

2. Follicular dysplasias

Question 20

Vibrissae and whiskers are a type of ________ hair.

Answer 20

Sinus [b/c they have an endothelium lined blood sinus, with rich nerve supply.]

Question 21

Tylotrichs are specialized hair scattered among other hairs that act as ______ _______ ________.

Answer 21

Rapid acting mechanoreceptors

Question 22

______ hairs are well anchored and do not pull out easily.

Answer 22

Telogen [this cycle dominates in most dogs, can remain in telogen for months to years.]

Question 23

T/F: The presence of telogen indicates a pathologic state.

Answer 23

False

Question 24

Hair replacement occurs in a ______ pattern.

Answer 24

Mosaic

Question 25

Thyroid and growth hormones, if normal initiate _______ and accelerate hair growth rate.

Answer 25

Anagen

Question 26

Dogs with long hair coats can take as long as _____ months to re-grow their hair post-clipping.

Answer 26

18

Question 27

Dogs with normal to short coats can take _____ to _____ months to re-grow their hair post-clipping.

Answer 27

3-4

Question 28

Alopecia that is always truncal, rarely involves the limbs or face and is bilaterally symmetrical is _______ and ________.

Answer 28

Non-inflammatory and non-pruritic

Question 29

Alopecia that is mostly truncal, often on the limbs and face, +/- symmetrical, and +/- has a moth eaten appearance is __________ and _________.

Answer 29

Inflammatory and non-pruritic