Dermatology

Question 1

Pustule

Answer 1

Small raised lump containing pus. Creamy-coloured, will see neutrophils if you put it on a slide.

Question 2

Papules

Answer 2

Small raised lumps <1cm

Question 3

Nodules

Answer 3

Small raised lumps >1cm

Question 4

Macule

Answer 4

Large lesion, usually less raised

Question 5

Wheal

Answer 5

AKA hives. Pruritic, erythematous sites.

Question 6

Urticaria

Answer 6

When wheals form all over the body in response to an allergic reaction.

Question 7

Vesicles

Answer 7

Sharply circumscribed elevations filled with fluid. Commonly caused by viral infections.

Question 8

Bullae

Answer 8

Larger vesicles

Question 9

Erosion

Answer 9

Partial loss of the epithelium, the basement membrane is INTACT. No innervation in epidermis so the animal may not even notice. As the basal layer is intact the cells are able to regrow very quickly.

Question 10

Ulceration

Answer 10

FULL THICKNESS- the basement membrane is BROKEN. Appear bloody, fluidy (cause of leakage of proteinaceous fluid). PAINFUL- may have loss of pigment and adnexal structures (alopecia) depending on severity.

Question 11

Lichenification

Answer 11

The skin takes on a thickened, crumpled appearance. Can occur everywhere but usually more evident in hairless regions. Usually indicates SYSTEMIC disease.infection

Question 12

Comedone

Answer 12

Effectively a pimple- swollen hair follicles.

Question 13

Epidermal collarettes

Answer 13

Effectively “old” pustules- ring of peeling skin?

Question 14

Depigmentation

Answer 14

Loss of pigment. Done purposefully in freeze branding

Question 15

Tumour

Answer 15

= Mass/lump. May be neoplastic (benign or malignant), inflammatory etc

Question 16

Crusting

Answer 16

Retention of the surface cells (i.e.the surface epithelium that is usually shed regularly) along with other debris, incl sebum, inflam cells etc.

Question 17

Dehiscence

Answer 17

The breaking down of a wound i.e. sutured site opening up again, esp after surgery.

Question 18

Erythema

Answer 18

= Redness, generally due to > blood flow

Question 19

Alopecia

Answer 19

Hair loss- due to disruption of adnexal structures.

Question 20

What is the function of fat in the hypodermis?

Answer 20

Cushioning, thermoregulation, storage of energy.

Question 21

Panniculitis

Answer 21

Inflam involving the hypodermis

Question 22

Cellulitis

Answer 22

Inflam involving underlying fascial planes as well as the panniculus and sometimes other parts of the skin.

Question 23

Phelgmon

Answer 23

Spreading diffuse inflam process w/ formation of suppurative/purulent exudate or pus caused by infection.

Question 24

What are the 3 causes of photosensitisation?

Answer 24

1. Genetic disorders that lead to production of photoactive compounds- this is rare.
2. As a result of ingestion of plants that contain primary photosensitising agents- they directly cause it.
3. Ingestion of plants/other causes of cholestatic hepatic disease- this results in phylloerythrin in herbivores, resulting in 2’ photosensitisation.