Autoimmune Skin Diseases (Marsella) Flashcards
Pemphigus complex
- Antibodies produced against protein (desmogleins) responsible for intercellular adhesion
- Type II hypersensitivity
- Detachement of cells from each other (acantholytic cells)
Pemphigus foliaceus location of action
Antibodies target antigens in the upper part of the epidermis (right below the stratum corneum)
Pemphigus foliaceus predilections
- Dogs, cats, horses, goats
- Chow-chow, Collie, Akita
- Middle-aged to old animals
Pemphigus foliaceus clinical signs
- Primary lesion: pustule
- Crusting & scaling
- Distribution: pinnae, face, bridge of nose, hyperkeratosis of footpads, nailbed (cats)
- Cat distribution (“stripper’s disease”): face, perinipple, nail beds
Pemphigus foliaceus diagnosis
- Cytology from pustule
- Histopath
- Biopsy new lesions (when off steroids)
- R/O pyoderma & demodex
Pemphigus foliaceus therapy
- Long term w/ potential serious side effects
- High doses of corticosteroids
- Azathioprine (dogs)
- Chlorambucil (cats)
- Gold
Pemphigus erythematosus predilections
- Collies
- German shepherds
Pemphigus erythematosus pathogenesis
- Cross over between pemphigus & lupus
- Milder than PF
- Antibodies
- Intercellular spaces of epidermis (pemphigus)
- Basement membrane (lupus)
Pemphigus erythematosus clinical signs
- Pustular dermatitis - face & ears
- Nasal depigmentation
- Aggravated by UV light
Pemphigus erythematosus diagnosis
- Cytology
- Histopath
- ANA test (antinuclear antibody) is negative
Pemphigus erythematosus therapy
- Mild
- Topical steroids or tacrolimus
- Sunscreen
- Severe
- immunosuppressive therapy
Pemphigus vulgaris predilections
- Most common type in humans
- Rare in animals, but usually older animals
Pemphigus vulgaris location of action
Acantholysis in lower epidermis
Pemphigus vulgaris clinical signs
- Primary lesion: bulla
- Ulcerations & erosions
- Distribution: oral cavity, mucocutaneous junctions, nail beds (sloughing), axillae, groin
- Lethargy, fever, anorexia
- 2º infections
Pemphigus vulgaris diagnosis
- Histopath
- Biopsy fresh lesions
- R/O more common diseases
Pemphigus vulgaris therapy and prognosis
- Immunosuppression - require high dose to stay in remission
- Prognosis guarded to poor, fatal without therapy
Pemphigus vegetans
- Very rare
- Mild form of pemphigus vulgaris
- Proliferative lesions
- Scaling, crusting of axillae and groin
- Diagnose & treat same as pemphigus foliaceus
Discoid lupus erythematosus predilections
- Collie
- German shepherd
Discoid lupus erythematosus pathogenesis
- Benign form of lupus
- Sunlight triggers expression of new antigens
- Produciton of antibodies
- Deposition in basement membrane
- Type II cytotoxic reaction
Discoid lupus erythematosus clinical signs
- Nose
- Depigmentation
- Loss of normal appearance
- Erosions & ulcerations
- Pinnae, eyelids, lips, footpads (rare)
Discoid lupus erythematosus diagnosis
- Histopathology
- Immunofluorescence
- ANA test (antinuclear antibody) - negative
Discoid lupus erythematosus therapy
- Topical steroids or tacrolimus
- Sunscreen, vit. E
- Systemic steroids (low dose) or tetracycline/niacinamide
Systemic lypus erythematosus pathogenesis
Antibodies produced against different antigens (RBCs, platelets, nuclear antigens…)
Dermatological signs of systemic lupus erythematosus
- Seberrhea
- Vasculitis - necrosis of pinnae and tip of tail, crusting and ulceration of footpads
- Nasal depigmentation & ulceration
- Mucocutaneous bullous disease
- Panniculitis
Systemic lupus erythematosus diagnosis
- Presence of multisystemic dz
- CBC, chem, UA
- Anemia, thrombocytopenia, proteinuria
- ANA test (antinuclear antibody test): 90%
- Suggestive histopath and immunofluorescence
Sysemic lupus erythematosus therapy
- Immunosuppressive drugs (high dose)
- Azathioprine
- Chlorambucil
- Gold contraindicated due to renal complications
Bullous pemphigoid predilections
- Old animals
- Collies
- Dobermans
Bullous pemphigoid pathology
Antibodies produced against basement membrane
(not a true pemphigus b/c no acantholytic cells and it acts in the basement membrane)
Bullous pemphigoid clinical signs
- Primary lesion: bulla
- Ulcerations
- Fever & anorexia
- Distribution: oral cavity, axillae, groin, mucocutaneous junctions, nail beds
- Paronichia (infection) , sloughing of nailes
Bullous pemphigoid diagnosis & therapy
- Histopath
- Immunofluorescence
- Immunohistochemistry
- Tx same as pemphigus foliaceus
Erythema multiforme pathogenesis
- Immune mediated syndrome
- 2º to drugs or infections (cephalosporins, TMP-sulfa, levamisole, gold)
- Acute, self-limiting
Erythema multiforme clinical signs
- Target lesions - peripheral erythema w/ central clearing
- Macules
- Plaques
Erythema multiforme diagnosis
- Suggestive history and clinical signs
- Histopathology - biopsy epidermis, not ulcer
Erythema multiforme therapy
- ID & tx underlying cause
- Supportive therapy
- Abx for 2º infection
- Steroids (controversial)
Toxic epidermal necrosis (general info)
- Severe cutaneous eruption
- Systemically ill - fever, lethargy
- Full thickness necrosis and sloughing
- Mucosal ulcerations
- Arthralgia
(usually induced by drugs, like Hartz products)
Toxic epidermal necrosis diagnosis
Histopath of early lesions
Toxic epidermal necrosis therapy & prognosis
- ID & tx underlying cause
- Supportive (fluids, abx)
- NO steroids
- Poor prognosis (electrolyte loss, 2º infections)
Mycosis fungoides pathogenesis
Cutaneous lymphoma (T cells)
CANCER (not a damn fungus)
Mycosis fungoides clinical signs
- Erythema, pruritis, seborrhea
- Depigmentation & ulcerations of mucus membranes & nose
- Stomatitis & oral ulcerations (animal stops eating)
- Plaques & nodules
Necrolytic migratory erythema (general info)
- AKA: hepato-cutaneous syndrome, glucagonoma syndrome, superficial necrolytis dermatitis
- Old dogs
- Associated w/ liver dz, glucagonoma, diabetes mellitus, Cushing’s
Necrolytic migratory erythema pathogenesis
- Metabolic defect - nutritional deficiency at epidermis → skin necrosis
- Aminoacids
- Zinc
- Fatty acids
- Cutaneous lesions may occur months before onset of systemic dz
Necrolytic migratory erythema clinical signs
- Erythema, ulcerations, crusting
- Distribution: pinnae, muzzle, footpads, genitalia
- 2º bacterial & yeast infections
Necrolytic migratory erythema diagnosis
- Histopath
- “Red, white, and blue”
- Blue - hyperplasia of basal cell layer
- White - cellular edema in middle epidermis
- Red - hyperkeratotic parakeratosis
Necrolytic migratory erythema therapy & prognosis
- ID & correct underlying dz
- Treat 2º infections
- Aminoacid, zinc, fatty acid supplement
- NO glucocorticoids
- Poor prognosis (death in 6 mos after onset of cutaneous lesions)
