Sebaceous Adenitis
Pigmentation disorders
Hypopigmentation
Hyperpigmentation
Eosinophilic infiltration
Eosinophilic plaques
- Common in cats
- Medial thighs and abdomen mostly involved
- Often associated with hypersensitivity
- Grossly:raised plaques, erythematous, pruritic, erosed or ulcerated
- Microscopically: acanthosis, spongiosis, erosions or ulceration, predominantly eosinophilic dermatitis, possibly areas of collagen degeneration
Eosinophilic granulomas
- Involves cats, dogs, horses
- Collagen degeneration in lesions os eosinophil degranulation
- Often involved in reaction to parasites, foreigh bodies or mas cell tumours
- Grossly:
- Papules, nodules, plaques, ulcers in skin
- Nodules or ulcers in oral mucosa of cats and dogs or on foot pads of cats
- Microscopically:
- Nodular dermatitis or stomatitis
- Fragments of degenerated collagen surrounded by eosinophils and macrophages
Eosinophilic folliculitis and furunculosis
- Rare in cats, dogs, cattle and horses
- Possibly due to arthropod bites
- May be multifocal in horses
Sterile granulomatous disorders
Juvenile pyoderma
- Also known as Juvenile sterile granulomatous dermatitis and lymphadenitis, juveline cellulitis, puppy strangles
- Involves dogs of less then 4 months of age
- Grossly: pustular and nodular dermatitis with oedema involving the face, ears, mucocutaneous junctions
- Microscopically: granulomatous or pyogranulomatous perifolliculitis, paniculitis and dermatitis
Equine generalised granulomatous disease
- Also known as Sarcoidosis
- In horses
- Rare
- Involves cutaneous lesions and systemic disease causing anorexia and weight loss
- Grossly: alopecia, scales, crusts, sometimes nodules and masses
- Microscopically: multifocal granulomas, multinucleated giant cells