Approach to Sinus Formation/Abscesses and Papular/Pustular Dermatoses PDF

Approach to sinus formation_ abscesses and popular and pustular dermatoses Dynatra Subasinghe BVSc, PG Dip., MSc, PhD, MRCVS, SFHEA Thursday, 31 August 2023 1  Part 1 Approach to sin...

Approach to sinus formation_ abscesses and popular and pustular dermatoses Dynatra Subasinghe BVSc, PG Dip., MSc, PhD, MRCVS, SFHEA Thursday, 31 August 2023 1  Part 1 Approach to sinus formation and abscesses 31/08/2023 2  How big is an abscess? 31/08/2023 Slide curtesy of S Mcintyre 3 Learning Outcomes 1.Understand the pathogenesis of sinus tract formation and abscesses 2. Describe and identify the typical presentations of sinus/abscess formation 3. Determine appropriate diagnostics when identifying causes of sinus formation 4. Determine appropriate medical and surgical approaches to treating X.sinus/abscess formation 31/08/2023 Slide curtesy of S Mcintyre 4 What is a sinus tract? ❖ A draining tract open to the skin surface ❖ A way for the body to expel unwanted material ❖ Achieved by production of pus 31/08/2023 Image – source https://www.slideshare.net/dimpunani/periodontal-abscess-30016884 5 What is an abscess? Staphylococcus aureus skin abscess formation in image Rabbit skin abscess 14 above days after infection Note that abscess can be sterile as well 31/08/2023 6 Images -Source - https://www.sciencedirect.com/science/article/pii/S000294401500070X What is an abscess? ❖Localised collection of purulent material ❖Fibrous capsule -can be very hard / may have a weak point ❖If bacteria / foreign body persists- chronic intermittent discharge through sinus Clinically – Locally - Observe signs of inflammation Pain – severe Redness Swelling Heat Loss of function – on a limb – lameness Systemic signs - may have fever, loss of appetite, lethargy 31/08/2023 Images -Source - https://www.pdsa.org.uk, https://www.animalwised.com 7 Pus ? Exudate consisting of WBC or liquefied tissue Can be sterile Comes in a variety of appearances (both smell and colour!) 31/08/2023 slide - curtesy of S Mcintyre 8 Causes of sinus tracts and abscesses? ❖Traumatic - penetrating trauma, foreign body ❖Inflammatory – due to bacterial infection ❖Neoplasia – mammary tumours on dogs ❖Secondary infection of primary skin disease - folliculitis, furunculosis, panniculitis ❖Iatrogenic - Sequelae of necrosis or subcutaneous rupture Images; curtesy of S Mcintyre, http://www.catbehaviourist.com 31/08/2023 9 What is your differential diagnosis? 31/08/2023 Slide curtesy of S Mcintyre 10 What is your differential diagnosis? Haematoma Lymphatic enlargement Cyst Seroma Neoplasia Granuloma Fibrous scar tissue Feel consistency – fluid filled, firm, is it attached to underlying tissue, location. etc… 31/08/2023 Slide curtesy of S Mcintyre 11 What is the diagnostic process? History Clinical signs Physical examination – palpation Other diagnostic tests ❖Swab –Culture and sensitivity ❖Smears / scrapes / FNA / cytology ❖Haematology /biochemistry (systemic) ❖Imaging? 31/08/2023 Selected Images - curtesy of S Mcintyre 12 Common causes of abscesses Primary causes Secondary process Penetrating Trauma: Deep pyoderma ❖ Cat bite abscess ❖ Demodex ❖ Cattle abscess ❖ Acral lick granuloma ❖ Hoof abscess Anal sacculitis/abscess Foreign body: Canine juvenile cellulitis ❖ Grass seed Sterile nodular panniculitis ❖ Stick injury Feline acne Neoplasia Feline Leprosy 31/08/2023 Slide curtesy of S Mcintyre 13 Approach to treatment? Open and drain FLUSH Remove nidus if possible Debride Antibiotics Pain relief Supportive treatment Owner advice 31/08/2023 Slide curtesy of S Mcintyre 14 Antibiotics? Is there a bacterial infection if so which bacteria? Use a pragmatic approach - origin of infection – in the history Possible organisms? Staph, Strep, E.Coli, Pseudomonas, Pasteurella, Mycoplasma, Fungal… Risks? Zoonotic MRSA (Staphylococcus pseudointermedius) Beware of What to choose? Anti microbial Broad spectrum ? resistance Length of treatment – rechecks 31/08/2023 15 Cat bite abscesses ❖ Common – (behavioural, territorial) ❖ Lesion – signs of inflammation ❖ Common locations - Tail base, shoulder, face, neck, legs ❖ Sinus tract maybe present ❖ Systemic signs - anorexia, pyrexia, lethargy ❖ Aggression due to pain and discomphort 31/08/2023 16 Images source - https://www.pdsa.org.uk, https://www.animalwised.com Deep pyoderma Bacterial infections involving the dermis and often subcutaneous tissues. Can be ulcerative crusty lesions with tissue oedema purulent haemorrhagic exudate Mucocutaneous pyoderma leading to crusting – crusts removed to show extensive erosion and ulceration 31/08/2023 17 Image source – Muller and Kirk, 2013  Grass seeds ❖ Very common in dogs – leads to pododermatitis and secondary bacterial infection ❖ Can migrate proximally - Surgical remove and flush Signs - Interdigital erythema Pustule, haemorrhagic bullae, abscess Draining sinus tract Pruritic –licking and chewing Can be chronic 31/08/2023 Image source – Muller and Kirk, 2013, www.vassevets.com.au 18 Anal sac disease 31/08/2023 Slide curtesy of S Mcintyre and image courtesy of https://www.pdsa.org.uk 19 Feline leprosy 31/08/2023 Slide curtesy of S Mcintyre 20 Feline leprosy 31/08/2023 Slide curtesy of S Mcintyre 21 Canine Juvenile Cellulitis/puppy strangles 31/08/2023 22 Slide curtesy of S Mcintyre Sterile nodular panniculitis 31/08/2023 Selected content curtesy of S Mcintyre 23  Summary 31/08/2023 Slide curtesy of S Mcintyre 24  Part 2 Approach to papular/pustular dermatoses 31/08/2023 25 Part 2- Approach to papular/pustular dermatoses Learning Outcomes ✓ Define papular/pustular dermatoses ✓ Identify pathological processes leading to papular/pustular dermatoses ✓ Describe the various diagnostic procedures to determine aetiology ✓ Discuss approach to appropriate management and treatment of diseases characterized by papular/pustular dermatoses ✓ Discuss appropriate prognosis, and the welfare implications of management and treatment options ✓ Discuss control measures appropriate for disease prevention where applicable Thursday, 31 August 2023 26 Approach to papular/pustular dermatoses Define Papule is a circumscribed, elevated, solid lesion Pustule is a small (< 1 cm in diameter), circumscribed superficial elevation of the skin that is filled with pus. May also be a vesicle filled with pus. Image credits – Muller and Kirk,2013 Thursday, 31 August 2023 27 Pustular diseases Classification Infectious Immune mediated Diagnostic tests Cytology Culture sensitivity (If infectious) Biopsy if necessary Image source – Muller and Kirk, 2013 Pyoderma - background Cutaneous defence mechanisms Behavioural – avoidance responses, grooming (removes parasites/cleans/distribute cutaneous secretions) Physical – hair, stratum corneum, Intercellular cement Chemical – fatty acids, cytokines, immunoglobulins and complement. Cells – Langerhan’s cells, mast cells, keratinocytes and T – lymphocytes Microbial - normal flora – symbiotic relationship in the skin exchanging growth factors and preventing invading bacteria from gaining a foothold – also can produce enzymes such as β- lactamase that inhibit antibiotic activity (antibiotic resistance?) Natures barrier Pyoderma Pathological processes – bacterial infections Pyoderma- a skin infection with formation of pus. can be primary or secondary (almost always) Primary pyoderma Secondary pyoderma Pyogenic bacterial skin infection with no 1. Allergy underlying cause 2. Ecto-parasites 3. Hormonal disease – Commonly seen in some breeds (Hypothyroidism, - e.g.- German shepherd dogs suffer from Hyperadrenocorticism) a deep primary infection 4. Keratinization disorders 5. Idiopathic add to the list … Thursday, 31 August 2023 Source – modified form Muller and Kirk,2013 30  Pyoderma – disease process – eg. Due to an allergy Few or no lesions Erythematous papules Pustules begin to appear Epidermal collarettes Healed former collarettes suggestive of early some collarettes in the Infection, process of healing beginning signs of superficial pyoderma Thursday, 31 August 2023 Source modified from - ©University of Wisconsin  Pyoderma – disease process – eg. Due to an allergy SNAP SHOT Few or no lesions Erythematous papules Pustules begin to appear Epidermal collarettes Healed former suggestive of early collarettes, Infection, some collarettes in the beginning signs of process of healing superficial pyoderma Thursday, 31 August 2023 Source modified from - ©University of Wisconsin  Pyoderma – disease process – eg. Due to an allergy SNAP SHOT Few or no lesions Erythematous papules Pustules begin to appear Epidermal collarettes Healed former suggestive of early collarettes, Infection, some collarettes in the beginning signs of process of healing superficial pyoderma Thursday, 31 August 2023 Source modified from - ©University of Wisconsin  Pyoderma – disease process – eg. Due to an allergy Few or no lesions Erythematous papules Pustules begin to appear Epidermal collarettes Healed former collarettes suggestive of early some collarettes in the Infection, process of healing beginning signs of superficial pyoderma Thursday, 31 August 2023 Source modified from - ©University of Wisconsin Pyoderma- causative organisms Bacteria Staphylococcus pseudintermedius 90% of canine pyodermas Primary cutaneous pathogen of dog Produces variety of substances including enterotoxins, toxic shock protein, protein A and haemolysins Increase adhesion to keratinocytes and act as superantigens that upregulate immune response Some strains produce slime that encapsulates the bacteria and inhibits phagocytosis whilst increasing it’s ability to adhere Pyoderma Classification 1. Surface pyoderma - Common in small animal practice. Bacterial infections of the epidermal layers of the skin. E.g. acute moist dermatitis, Intertrigo 2. Superficial pyoderma - Pustule formation within the epidermis or hair follicle. E.g.- Impetigo, Mucocutaneous pyoderma, Superficial bacterial folliculitis 3. Deep pyoderma –Bacterial infections of the dermis and subcutaneous tissues. Intertrigo – skin fold dermatitis Surface pyoderma Bacterial infections that involve the epidermal layers of the skin Facial fold intertrigo – English bull English bulldog. After an allergy - dog - staphylococcal overgrowth Malassezia overgrowth is present Image source – Muller and Kirk, 2013 Bacterial Vs fungal Tape / impression smear sytology Degenerate neutrophils Bacteria in neutrophils Yeast – Malassezia overgrowth in an impression smear – peanut / foot print shaped organisms Image source – Muller and Kirk, 2013 Impetigo Superficial pyoderma Bacterial infections that involve the epidermal layers of the skin and the formation of pustules in the epidermal layer Commonly seen in puppies Causes - maybe due to immune compromise gastrointestinal parasites (worming), parasitism (parasite treatment) other viral infections (vaccination), poor nutrition (diet improvement), dirty environment (clean environment), etc.. They are not painful and rupture easily, leaving a peripheral epidermal collaret or crust adherent to the skin. Signalment and lesions diagnostic – when correct above puppy care aspects lesions disappear Image source – Muller and Kirk, 2013 Bullous impetigo Superficial pyoderma Bacterial infections that involve the epidermal layers of the skin and the formation of pustules in the epidermal layer Signalment - older dogs, haired regions Immunodeficiency Primary cause Hyperadrenocorticism Diabetes mellitus Hypothyroidism etc. Discussed in detail later Image source – Muller and Kirk, 2013 Pyoderma- classification Deep pyoderma Bacterial infections involving the dermis and often subcutaneous tissues. Can be ulcerative crusty lesions with tissue oedema purulent haemorrhagic exudate Mucocutaneous pyoderma leading to crusting – crusts removed to show extensive erosion and ulceration Image source – Muller and Kirk, 2013 Pyoderma- Diagnostics Degenerate neutrophils 1. Diagnostics for underlying disease 2. Cytology – impression smear Bacteria in neutrophils 3. Culture and antibiotic sensitivity testing – as appropriate How do you take a MRSP and MRSA – importance increasing sample ? Cost/benefit Essential – referral cases – first opinion? - deep pyoderma can use sterile swabs to sample Thursday, 31 August 2023 Image source – Muller and Kirk, 2013 42 Pyoderma – treatment Treat underlying disease - if there is one Beware of Antibiotics – local- topical / systemic Anti microbial Antibiotic stewardship -Treat for long resistance enough at correct dose- owner compliance important Shampoo – topical Keep monitoring progress !!!! Antibiotics Systemic antibiotics Only use - where bacteria have been demonstrated positive cytology or bacterial culture lesions too severe and widespread to respond to topical therapy alone A course of antibiotics Should best be given for an appropriate duration at an adequate dose Stress importance of client compliance. Good communication! Systemic antibiotics Amoxicillin clavulanate – 12.5mg/kg twice a day /bid. Cephalexin - 22mg/kg twice a day /bid. Clindamycin - 11mg/kg twice a day /bid. Potentiated sulphonamide- 15-30 mg/kg twice a day /bid. Cefovecin - 8 mg/kg single dose or as per manufacturer guidelines Note - Fluoroquinolones should be reserved for Gram-negative infections Shampoos Local action Chlorhexidine shampoos Ethyl lactate Image- www.shutterstock.com Summary Pyoderma Approached in a methodical fashion with clinical reasoning Primary cause ? (allergy, endocrine disorders) Client communication – professional relationship vital to a good prognosis A diagnosis can provide owner with a realistic prognosis Treatment plans are essential – write it down in the notes – if multiple vet practice – keep reviewing case regularly Referral - Choose cases - optimise management – reduce owner frustration – improve animal welfare Pustular disesases Immune mediated diseases 1. Phemphigus foliaceous – most common 2. Sterile eosinophilic pustulosis Modified from - ttp://healthequityexchange.com Pemphigus foliaceous Immune mediated diseases Autoimmune disease Target antigen – Dsg 1- (desmogleen one) in humans and dogs. Cat unknown Acantholysis – the separation and breakdown of skin cells due to tissue- bound antibody deposits in the space between cells. Causes Idiopathic – majority Medications Allergy? Signalment – Both cats and dogs Age - mean age of onset 7 years Breed - Genetic – Akita’s and chow chows Image source – Muller and Kirk, 2013 Pemphigus foliaceous Immune mediated diseases Clinical signs – dermatological lesions Pustular erosive crusting lesions Lesions often are symmetrical Lesion locations – ears, nipple area, nose, foot pads etc...-nasal depigmentation may occur Lesions look like epidermal collates with time The pustule is sterile no bacteria is observed Image source – Muller and Kirk, 2013 Pemphigus foliaceous Immune mediated diseases Clinical signs – dermatological lesion locations Starting form the head, ears, and footpads. Often becomes generalized over the body Gums and lips Footpad overgrowth and cracking can be seen Cats - nipples and nail beds affected Image source – Muller and Kirk, 2013 Phemphigus foliaceous Immune mediated diseases Diagnosis Through history - animal’s health onset of symptoms possible incidents – that may have precipitated the condition Through – general physical exam - blood chemical profile - complete blood count - urinalysis - electrolyte panel Pemphigus – often - normal results for blood tests Image source – Muller and Kirk, 2013 Phemphigus foliaceous Immune mediated diseases Diagnosis cd… Through – dermatological examination Lesions Laboratory tests 1. Cytology Characteristics – Non degerative neutrophils Pustule – cytology- clump of acantholytic cells and some neutrophils and Acanthocytes acantholytic keratinocytes eosinophils – note intact cells No bacteria (usually) If bacterial present it will be a secondary infection Image source – Muller and Kirk, 2013 Phemphigus foliaceous Immune mediated diseases Diagnosis cd… Laboratory tests cd… 2. Biopsy - helpful - invasive Biopsy – Histopathology –Pemphigus foliaceous- acantholytic cells with neutrophils Image source – Muller and Kirk, 2013 Phemphigus foliaceous Immune mediated diseases Treatment ✓Glucocorticoids ✓Cyclosporine ✓Azathioprine ✓Chlorambucil ✓Tetracycline and Niacinamide ✓Mycophenolate Mofetil Aim for lowest possible dose to decrease side effects Management – regular check ups- blood tests – after signs subside – keep checking Minimize sun exposure Prognosis – guarded with regular monitoring References https://www.universalmedicalinc.com/canine-skin-model.html- downloaded 09-08-18 Jackson., H, Marsella., R., (2012). BSAVA Manual of Canine and Feline Dermatology, 3rd Edition., Wiley: ISBN: 978-1-905-31927-5 Miller, W. H., Muller, G. H., Scott, D. W., Griffin, C. E., & Campbell, K. L. (2013). Muller and Kirk's Small Animal Dermatology. St. Louis, Mo: Saunders. Nielsen, TD., Dean, RS., Robinson, NJ., Massey, A., Brennan, ML. (2014) Survey of the UK veterinary profession: common species and conditions nominated by veterinarians in practice Veterinary Record 174, 324. Maddison., J. M., Volk h. A., Church d. B., (2015) Clinical Reasoning in Small Animal Practice.; Wiley- Blackwell; ISBN: 978-1-118-74175-7  Thank you