Autoimmune And Immune-Mediated Skin Diseases Flashcards
What are 3 examples of autoimmune skin diseases?
Pemphigus complex, discoid lupus erythematosus (DLE), Bullous pemphigoid
Antigen becoming foreign to the body is an example of ____ ______ reaction
immune mediated
Hallmark of ___ disease is acantholysis
pemphigus
what is the definition of acantholysis?
breakdown of epidermal intercellular adhesion-> separated keratinocytes
What is the major autoantigen in pemphigus foliaceus?
Desmocollin 1 (Dsc 1)- major and Desmoglein 1 (Dsg 1) - minor
What form of pemphigus is most common?
Pemphigus foliaceus
Signalment for PF
Middle aged to older dogs, more than 1 year old Chows, Akitas, cockers, dauschund, labs, bullies
Idiopathic PF
Drug induced from cats with Cimetidine, itraconazole, lime sulfur
dogs with amitraz
CS of Pemphigus foliceous
Pustules – spanning multiple follicles
Papular dermatitis
Crusts
All lesions usually bilateral on head, face, ears, footpads
What is the timing of progression of PF?
Disease development is rapid (1 to 2 w) or insidious (1 to 2 or more months)
Cats with PF:
similar to dogs but have crusty claw fold (paronychia) lesions and lesions around the teats
Diagnosis of PF and TX
Cytology of pustules or underneath the crusts, confirmed via histo with subcorneal pustule with acantholytic cells
TX is pred/steroids =, frequent rechecks
What is a med for dogs with PF BUT NOT CATS?
Azathioprine
Why do we need several rechecks with a patient with PF on tx?
to determine when to taper and to determine need to add other medications
What disease is a crossover between PF and DLE?
Pemphigus erythematosus where there is crusts on the face and depigmentation of nose
What disease is more severe but less common than PF and causes vesiculobullous lesions with oral and mucocutaneous lesions, some claw bed sloughing, and febrile, depressed, anorexic patient?
pemphigus vulgaris
on histo, we see suprabasilar intraepidermal cleft with basal cells. What is the disease?
Pemphigus vulgaris
What is a benign*** disease without systemic signs that causes lesions on the face and ears EXACERBATED BY UV LIGHT???
Discoid Lupus Erythematosus aka Cutaneous LE
Lesions of Discoid Lupus Erythematosus aka Cutaneous LE begin where?
The junction of the haired skin and nasal planum and extend up the nose
Erythema Mulitforme (EM) vs. Toxic Epidermal Necrolysis (TEN)
- Both = terms used for patterns diagnosed on histopathology with certain clinical features (lesions on skin)
- Triggered by something,are immune mediated
- Has to be figured out clinically – commonly linked to cutaneous drug reactions
What disease is not common in dogs nor cats and is often linked to drugs (TMS, Pen, cephalosporins)???
Erythema multiforme (EM)
Distribution of lesions for Erythema multiforme (EM):
Ventrum – axillary, inguinal
MC junctions & oral cavity
Pinnae
Footpads
Severe or acute/peracute disease with vesicles turning to ulcers and full thickness necrosis of the epidermis is what disease?
Toxic Epidermal Necrolysis (TEN)
Bullous pemphigoid involves antigbodies (IgG) against the ____ _____ causing dermo-epidermal separation and oral ulcers + vesicles, bullae
basement membrane
Histopath showing dermoepidermal clefts often with inflamm. cells =
Bullous pemphigoid
? has more severe and deeper lesions than ? which has pustules erupting to crusts
Pemphigus vulgaris; pemphigus folicaeous
What is the most common Autoimmune skin disease in dogs/cats?
PF
Acantholytic cells on cytology of pustules is highly suggestive of….
PF
should you scrub crusts before histo sample?
No, just clip hair
Depigmentation of nasal planum plus some erosions and ulcers of the nasal planum=
PE (pemphigus erythematosus)
Tx of DLE
Vit E, FA, doxy, topical steroids
Which two diseases are immune mediated where the antigen is foreign to the body?
Erythema multiforme and toxic epidermal necrolysis
Erythema multiforme and toxic epidermal necrolysis are terms that both mean what?
Patterns diagnosed on histopath with certain clinical features (lesions on the skin), triggered by something, and linked to cutaneous drug rxns (TMS, Pen, Cephalosporins)
Toxic epidermal necrolysis tx
Discontinue Cephalosporin, TMS, or penicillin, fluids, abx, and steroids
What are the two autoimmune disorders?
Pemphigus complex and DLE
What are the two immune mediated disorders?
Erythema multiforme and toxic epidermal necrolysis
