Draining sinus tracts- 2

Question 1

How to approach treating infectious draining sinus tracts

Answer 1

they generally affect deep skin/ subcutis
systemic treatment for min 2 weeks
ABs- based off C and S
avoid immunosuppressive drugs
consider underluing cause

Question 2

which skin strutures are involved in deep pyodermas

Answer 2

Infection outside epidermis or hair follicle epithelium

Question 3

What are the three most common manifestation of a deep pyoderma

Answer 3

Furunculosis
Abscess
Cellulitis

Question 4

How does furunculosis usually develop

Answer 4

Extension of folliculitis –> rupture of hair follicle wall –> microbes + free keratin in dermis –> provokes a foreign-body reaction

Question 5

What type of inflammation is present in furunculosis ? How will you recognise this on cytology

Answer 5

Usually pyogranulomatous reaction – see macrophages, neutrophils +/- rbcs
NB organisms may be hard to find – do not assume is sterile!

Question 6

How do you treat bacterial furunculosis

Answer 6

Usually systemic Abs based on C and S - continue 2 weeks post-resolution
Topical chlorhexidine shampoos/foams also

Question 7

Why does inflammation often persist, even after bacterial infection is resolved in furunculosis

Answer 7

Inflammation may persist after infection resolved due to foreign body reaction to keratin – at this stage may therefore need anti-inflammatory medication (corticosteroids/ ciclosporin/ tacrolimus)

Question 8

List 6 specific presentations of furunculosis

Answer 8

chin/muzzle folliculitis/ furunculosis
Nasal folliculitis/furunculosis
Interdigital folliculitis/furunculosis*
Acral lick dermatitis/granuloma*
Post-grooming folliculitis/furunculosis*
German Shepherd Dog pyoderma (rare)

Question 9

what organism is most commonly involved in deep pyodermas

Answer 9

staphylococcal infections

Question 10

List 5 things furunculosis can occur secondary to

Answer 10

allergies
ectoparasites
infections
systemic immunosuppression/ endocrinopathy
pressure driving hair back into skin

Question 11

Describe lesions in Interdigital folliculitis/furunculosis

Answer 11

Lesions originate on palmo-plantar surface of foot but rupture as draining sinus tracts on dorsal aspect- starts sterile then becomes infected

Question 12

List 3 predisposing causes of interdigital folliculitis/ furunculosis

Answer 12

breed- e.g. english bull terrier
increased weight-bearing
altered weight bearing

Question 13

how to approach clinical case of interdigital folliculitis/ furunculitis

Answer 13

1. consider primary cause- e.g. demodicosis
2. investigate and treat secondary inf
3. control inflammation once infection controlled
4. address predisposing triggers where possible

Question 14

when do we use surgery to treat interdigital folliculitis/ furunculosis

Answer 14

For end-stage disease, refractory to medical management

Question 15

List 4 possible underlying causes of acral lick dermatitis/ granuloma

Answer 15

pruritus
pain
neoplasia- uncommon
anxiety/ boredom

Question 16

what is acral lick dematitis granuloma

Answer 16

– a deep pyoderma but does not present with sinus tracts - a d/d for cutaneous masses!

Localised folliculitis/furunculosis on lower limbs due to self trauma – frustrating condition!

Question 17

which dogs generally get acral lick dermatitis granuloma

Answer 17

large, middle- aged/ older dogs

Question 18

diagnosis of acral lick dermatitis granuloma

Answer 18

often visually distinctive
cytology (squeeze lesion)- deep bacterial culture ideal
biopsy- if unsure if neoplasia or deep fungal infection

Question 19

treatment of sever case of acral lick dermatisi granuloma

Answer 19

treat deep pyoderma
physical prevention of licking
control inflammation once infection controlled
behavioural modification
very frustrating cases- need to adress early

Question 20

define cellulitis

Answer 20

ill-defined deep inflammation involving deep s/c connetive tissue

Question 21

Treatment of foreign body - interdigital

Answer 21

Poultice/bathe to‘draw’, then explore carefully UGA with alligator forceps –> emove FB

Avoid antibiotics till explored!

Question 22

what is Bacterial granulomatous dermatitis caused by

Answer 22

caused by traumatic implantation of saprophytic organisms

Question 23

List the 2 causative agents of mycobacterial infections in cats

Answer 23

1. Mycobacterium tuberculosis complex (MTBC)- need to notify APHA or UK health security agency
2. Non-tuberculous mycobacteria (NTM)

Question 24

List the 4 subgroups of non-tuberculoous mycobacteria

Answer 24

Mycobacterium leprae complex (MLC)
M avium complex (MAC)
Slow-growing NTM
Rapid-growing NTM

Question 25

Signs seen with mycobacterium tuberculosis complex

Answer 25

Localised cutaneous nodules +/- ulcers/draining tracts, especially ‘fight and flight’ sites – face, extremities, tail base +/- localised/generalised lymphadenopathy +/- GI disease, lung disease, weight loss, pyrexia

Question 26

Signs seen with non-tuberculosis mycobacteria

Answer 26

Cutaneous or s/c nodules diffuse panniculitis variably painful disseminated disease uncommon

Question 27

How to diagnose mycobacterial granulomas/ pyogranulomas infections in cats

Answer 27

biopsy- any non-resolving skin lesions cytology- mixed inflammatory cells culture IFN- gamma-release assay PCR

Question 28

Treatment of mycobacterial granulomas/ pyogranulomas

Answer 28

ABs- long course- based on C&S- 2 months post-resolution Wide surgical resection where possible – likely curative for FLS

Question 29

how do subcutaneous (deep) fungal infections presented

Answer 29

cutaneous papules or s/c nodules +/- ulceration/discharging tracts/tissue +/- tissue granules/grains Usually due to traumatic implantation of fungus - most commonly on feet/limbs or head

Question 30

Decsrieb systemic mycoses

Answer 30

Can affect any organ system, including skin---> granulomas/pyogranulomas/necrosis in organs affected will be systemically ill e.g. Cryptococcosis – zoonotic!

Question 31

A 9yo Rottweiler presents with discharging sinuses on the muzzle. Which investigations will you perform first

Answer 31

Examine an impression smear of the exudate and deep skin scrapes