Autoimmune, immune-mediated & inflammatory diseases Flashcards
Describe autoimmune diseases broadly.
Are very rare.
Autoantibodies, reaction to antigen.
Sometimes very acute presentation, sometimes waxing and waning.
If suspicion - skin biopsy (doesn’t respond to treatment, erosions, ulcers, middle-aged animals, structural changes on nasal planum, pustules-vesicles-crusts).
The most common auto immune disease in small animals?
pemphigus foliaceous
Name two autoimmune disease groups
and diseases that belong to each group.
Pemphigus group:
* Pemfigus foliaceus (PF)
* Pemfigus erythematosus
* Pemfigus vulgaris
* Mucous membrane pemfigus
Lupus group:
* Discoid lupus erythematosus (DLE)
* Systemic lupus erythematosus (SLE)
These are in contrast to immune-mediated and inflammatory diseases!
Name 8 Immune mediated and inflammatory diseases.
Drug reactions
Erythema multiforme
Eosinophilic cellulitis / Well’s-like syndrome
Juvenile cellulitis
Perianal fistulas
Sebaceous adenitis
Symmetric lupoid onychodystrophy (SLO)
Vasculitis
These are in contrast to autoimmune diseases!
Describe Perianal fistulas, perianal furunculosis.
● Unknown etiology. Chronic ulcerating/fistulating inflammation of the perianal region.
● Lesions are painful, different sizes fistulas, fissures. Not related to perianal glands! Mucopurulent exudation and licking might be present.
● On rectal palpation thickening of the rectum and anus.
● Often owners notice defecating problems.
● Frustrating problem!
german shepherds and middle aged dogs typically
Treatment of perianal fistulas.
● Cyclosporine 5mg/kg q12-24 h. It might take months for the lesions to resolve. Animals might need to stay on treatment permanently.
● As an alternative or in the beginning of cyclosporine treatment - prednisolone 2mg/kg q24h for 2 weeks or until lesions resolve, then tapered down.
● Topical: corticosteroids e.g. clobetasol, tacrolimus/pimecrolimus q12 h until lesions resolve, then tapered down.
● Local hygiene (chlorhexidine)
● Give pain meds & laxatives, if needed.
● Surgery if there are refractory areas not responding to drugs but not for the whole of the anal region.
● Elimination diet could potentially help. Some hypothesis that food allergy might contribute to these.
● Antimicrobial therapy for secondary infections if needed.
4 months old male siamese kitten Pätu, in a new home for 2 months. Emergency visit. Owner visited local clinic a week before because she noticed crusts on ear pinna and cat was trembling/shivering.
The scrapes were done for parasites - neg. Temperature was 39.0’C. Cat received cefovecin (Convenia), simeticone (Espumisan) and dewormer (no name known).
One day later, owner noticed crusting on the nose, toes. The cat is pruritic. They returned to the clinic and Pätu had fever 40.5’C. He doesn’t want to play, but has been eating, drinking.
Your ddx? (6)
Ddx - pyoderma, dermatophytosis, drug reactions, autoimmune diseases (pemfigus foliaceus), mosquito bite hypersensitivity, (epitheliotropic lymphoma)
Do cytology and histopathology to find out.
nail bed crust and inflammation is called
paronychia
Describe pemphigus foliaceous in cats.
Paronychia, crusting on the nose, ear pinnae, lesions around the nipples. Hypopigmentation and loss of architecture on the nasal planum. Pustules - crusts - epidermal colarettes - alopecia.
Fever if generalized disease. Might be pruritic.
Autoimmune disease: antibodies against desmosomes between keratinocytes on basal membrane. Sometimes triggered by drugs (also spot ons). Worsened by uv-light.
Treatment: immunosupressive therapy that might be lifelong.
In cats: prednisolone (dexamethasone in some cases), cyclosporine, oclacitinib, chlorambucil.
Case 3. 7 y/o male dog. 2 weeks ago owner noticed a hole in the nail. Dog was licking and limping. Trauma was suspected in another clinic and NSAIDs and unknown cream prescribed.
Dog continued to lick the feet and there was intermittent limping. A week before visit licking progressed. Owner noticed many nails detaching from the nailbed and falling off!
The dog has lost 3 nails and 1 is loose.
Ddx? (6)
bacterial and fungal infections,
drug reactions,
vasculitis,
neoplasia,
symmetric lupoid onychodystrophy (only disease that would have symmetric presentation)
Diagnosing through classical clinical signs, rule out differentials,
histopathology if needed (amputation of P3).
word for when the nail plate separates from the nail matrix and nail bed, eventually leading to shedding of the nail
Onychomadesis
Onychalgia = nail pain
Onycholysis = painless detachment of the nail
Onychodystrophy = Abnormal changes in the shape, color, texture, and growth of the nails.
Describe SLO - symmetrical lupoid onychodystrophy.
Immune-mediated inflammation that causes onychomadesis and onychodystrophy.
Paronychia in case of secondary infection. Otherwise healthy animals.
Initially only 1 or 2 nails fall off which are often suspected to be trauma - until the rest of the nails begin to follow suit.
the nails fall out and the new ones that grow in are dystrophic
SLO treatment
Clipping or removing loose nails, as short as you can.
Omega fatty acids 180mg EPA for 4.5kg. Results in 3
months.
- Cyclosporine 5-10mg/kg daily, for at least 3 months.
- Pentoxifylline 10-25mg/kg 8-12 h
- Prednisolone 2mg/kg
- Topical steroids/tacrolimus
Might need lifelong treatment.
Pain medication, secondary infection treatment if needed.
Pentoxifylline does what?
improves blood flow
mild vasodilation
anti-inflammatory
used in vasculitis, laminitis and SLO etc.
7 years old mixed breed dog, male, taken from the shelter. 4 months history of crusting, bleeding and loss of pigment on the border of nasal planum and hairy skin. Sometimes sneezes. Rarely any pruritus seen.
Your ddx? (6)
● Nasal pyoderma
● Solar dermatitis
● Neoplasia
● Discoid lupus erythematosus
● Pemfigus foliaceus
● Pemfigus erythematosus
Ended up being DLE.
Describe DLE.
Discoid (Cutaneous) Lupus Erythematosus
About as common as pemphigus foliaceous so not terribly rare.
Autoimmune disease of dogs and cats (cats tend to have crusting on ears and face).
Is a “Benign” form of lupus erythematosus.
Triggered by UV light suspected.
Prognosis is good, but might need life-long therapy with immunosupressive drugs + topical treatment + sunscreens.
Case 5. Female mixed breed Taksik.
Hospitalised for acute joint pain. Dog doesn’t like to be held, elbows are really painful. In the clinic, the dog developed facial edema, otitis (exudation on the ear pinna). Enlarged lymph nodes.
Ddx? (5)
Pyoderma (furunculosis)
Demodicosis
Angioedema
Canine distemper (can sometimes cause face crusting but is not a common sign)
Juvenile cellulitis aka puppy strangles
Describe juvenile cellulitis in dogs.
“puppy strangles”
Unknown pathogenesis. Rare disease! Might be genetic.
Affects puppies from 3 weeks to 6 months. Predisposed breeds include dachshunds, labrador and golden retrievers, gordon setters, beagles.
More than one puppy in a litter might be affected.
Vesicles, pustules, crusts, papules, alopecia on the
muzzle, eyelids, nose. Ear pinnae might be exudative and edematous. Lesions might be painful, but not usually pruritic.
Lymphadenomegaly might be seen with lymph
node abscesses. Puppies might be febrile and in bad condition. A few cases report joint pain.
Diagnosis and tx of puppy strangles.
Rule out other differentials. FNA from lymphnodes show no infections. Culture is usually negative. Infections are rarely seen on cytology. Histopathology?
Tx with Prednisolone 2mg/kg q 24 h until in remission (1-4 weeks). Then slowly tapered down in every 2-3 weeks. Relapses might be seen if tapering is too quick.
Prognosis is good, if remission happens in a week or two. Scarring might be seen. Disease might be fatal if not treated.
Case 6. 2 years old german shephard male, Dali
Dog had vomiting and diarrhea, then owner noticed erythema on the eyelids. Quickly progressed into edema on the face, paws and erythematous lesions
appeared. Dog is in bad condition - depressed, weak, anorectic.
Ideas?
Turned out to be Eosinophilic cellulitis/dermatitis - Well’s like syndrome based on histopathology.
target lesions
Describe Eosinophilic cellulitis/dermatitis - Well’s like syndrome. (Canine Acute Eosinophilic Dermatitis with Edema)
Immune-mediated disease, exact pathogenesis unknown. Quickly progressing erythematous macules, wheals, plaques on ventral abdomen, ear pinna and sternum. Edema on the face and all over body.
Often negative diascopy. Can have initial gastrointestinal signs 1-10 days before skin lesions.
Treatment: removing suspect drugs, treat with corticosteroids prednisolone 1mg/kg twice daily, antihistamines, paracetamol, antibiotics (amoxicillin + clavulanic acid) for secondary infections.. Usually responds to treatment quickly. Sometimes waxing and waning.
Case 7. 5 years old french bulldog Rocky.
Dog has been to another clinic all his life because of allergy. These lesions developed quickly as reported by the owner. Emergency visit because of crusting all over the body, purulent exudate. The dog was hospitalised because of hypoglycemia.
Unknow pruritus score, because dog was removed from the owner. Some scratching seen in the clinic.
What would be your differentials? (7)
● Secondary infections
● Demodicosis, sarcoptosis
● Dermatophytosis
● Drug reactions
● Epiteliotropic lymphoma
● Autoimmune diseases
● Hepatocutaneous syndrome
The hypoglycemia could be a sign of sepsis.
Describe hepatocutaneous syndrome.
Hepatocutaneous syndrome in dogs, also known as superficial necrolytic dermatitis (SND), is a rare but severe skin disorder most commonly associated with chronic liver disease or, less frequently, glucagon-secreting pancreatic tumors.
It is characterized by painful, crusted, and erosive skin lesions that typically affect the footpads, face, ears, and areas of friction such as the groin and muzzle. These skin changes result from amino acid deficiencies caused by liver dysfunction, leading to poor skin regeneration and healing.
Affected dogs often present with lethargy, weight loss, and signs of liver disease, and the condition is diagnosed through a combination of blood tests, imaging, and skin biopsies.
Prognosis is guarded, but supportive care with intravenous amino acid supplementation, dietary management, and treatment of underlying liver disease can improve quality of life.
