Case 13

Female 85. Recurrent urinary tract infections, and rash over fingers and dorsal thumb.

The best diagnosis is:

A. Pyodermatitis /Pyostomatitis vegetans

B. Neutrophilic dermatosis of the dorsal hands

C. Squamous cell carcinoma

D. Atypical mycobacterial infection (M.chelonae)

Case 13Female 85. Recurrent urinary tract infections, and rash over fingers and dorsal thumb.

Case 13

Female 85. Recurrent urinary tract infections, and rash over fingers and dorsal thumb.

The best diagnosis is:

A. Pyodermatitis /Pyostomatitis vegetans

B. Neutrophilic dermatosis of the dorsal hands

C. Squamous cell carcinoma

D. Atypical mycobacterial infection (M.chelonae)

Courtesy K Semkova & W Rickaby

Neutrophilic dermatosis of the dorsal hands – another case –subepiodermal oedema like in Sweet’s

Focal leukocytoclastic vasculitisCommoner in neutrophilic dermatosis of dorsal hands than Sweet’s

Courtesy K Semkova & W Rickaby

Neutrophilic dermatosis of dorsal hands

• also palms/fingers cf widespread in Sweet’s syndrome• Rarely systemic unlike Sweet’s• Like Sweet’s associated with underlying conditions includinginfection (UTI commonest as in this case) and malignancy

• Leukocytoclastic vasculitis commoner than Sweet’s

Rook’s Textbook of Dermatology 9th ed (Wiley): Neutrophilic dermatoses differential diagnoses

• Pyoderma gangrenosum and variants

– classical ulcerative

– parastomal, pustular, bullous

– granulomatous superficial PG

– Neutrophilic dermatosis of the dorsal hand

– Extracutaneous PG

• Sweet’s disease & variants

– Neutrophilic dermatosis of the dorsal hand (Favoured to be Sweet’s variant rather than PG)

– Subcutaneous Sweet syndrome

– Histiocytoid Sweet syndrome

Rook’s Textbook of Dermatology 9th ed (Wiley): Neutrophilic dermatoses

• Bowel-associated dermatitis arthritis syndrome

• Subcorneal pustular dermatosis (Sneddon-Wilkinson)

• Other neutrophilic dermatoses and variants:

– Pyodermatitis-pyostomatitis vegetans

– Antimicrobial pustulosis of the skin folds

– Aseptic abscess syndrome

Rook’s Textbook of Dermatology 9th ed (Wiley): Autoinflammatory diseases

• periodic fevers;

• cryopyrinopathies;

• familial Mediterranean fever; TRAPS; CAPS; CANDLE; DIRA;

• DITRA; PAPA;

• Schnitzler syndrome;

• adult-onset Still disease

Courtesy Lynne Jamieson

• Male 25 with Crohn’s disease for 4 years

• Six week history of oral ulceration with cobblestone oral mucosa and confluent pustules on lips, associated with confluent vegetative plaques (mildly exudative) in the groin (bilaterally), mons pubis and perineum

Differential diagnosis:Pyodermatitis /Pyostomatitis vegetans

Courtesy Lynne Jamieson

Histopathological features: • Pseudoepitheliomatous hyperplasia • Intraepithelial / subepithelial abscesses

containing large numbers of eosinophils • Acantholytic keratinocytes

• Direct and indirect IMF: Negative

Pyodermatitis /Pyostomatitis vegetans

Clinical course tends to run parallel to that of the IBD

• ? excessive immune response to gut bacteria• 1-6 years following bowel bypass surgery.• Recurrent episodes of fever, myositis• Non-destructive polyarthritis, tenosynovitis

Bowel-associated dermatitis-arthritis syndrome (BADAS)

• clinically Sweet’s like• erythema nodosum• papules, blisters, pustules on

trunk and proximal arms

Histopathology –• neutrophilic dermatosis:

Sweet’s-like, oedema

Differential diagnosis:Squamous cell carcinoma

Any time there are neutrophil microabscesses & histologically tempted to diagnose SCCthink: Could this be reactive? Differential diagnosis of SCC with neutrophils:

• Keratoacanthoma• Infection• Pyoderma gangrenosum• Sweet’s & variants

Differential diagnosis:

classical pyoderma gangrenosum:

typical “undermining” of surface by abscess

Superficial granulomatous pyoderma gangrenosum

• Idiopathic, especially on trunk, chronic often• Ulcer with superficial abscess rimmed by granulomatous inflammation• Haemorrhage, foreign material in ulcer bed eg hair shafts, vegetable matter • Usually superficial but can extend more deeply• Pseudoepithleiomatous hyperplasia• Culture to exclude infection

Role of biopsy in neutrophilic dermatoses

Biopsy useful –

• a) for histology

• b) culture to exclude infection

• But – need deep incisional biopsy or risk misinterpretation

Neutrophil-rich dermatoses -infections

Neutrophil-rich dermatoses -infections

Common

• abscesses

• cellulitis

• (necrotising fasciitis)

• mainly bacterial

• may require surgical incision, drainage and culture

• consider biopsy for histology if not responding to treatment

Neutrophil-rich dermatoses -infections

• atypical mycobacteria

• fungal infection:– Superficial: on biopsy many lack neutrophils, neutrophil rich

intracorneal pustules in some

– Deep: similar histology to atypical mycobacterial infection

• Immunosuppression:– requires full panel of special stains,

– may require immunohistochemistry for viruses, culture, serology etc

• rarer infections – often neutrophil component

Atypical mycobacterial infection

M.chelonae

Pseudoepitheliomatous hyperplasia of epidermis common

Atypical mycobacterial infection:suppurative granulomatous inflammation i.e. collections of neutrophils as well as macrophages

“hole” in the dermis: but not empty

Ziehl-Neelsen: “holes” in the dermisfilled with acid fast bacilli M. chelonae – often see lots of mycobacteria unlike many otheratypical mycobacterial infections

Cutaneous Atypical Mycobacterial Infection

Clinical features variable:

•Verrucous nodules•Erythematous nodules•Ulcer•Abscesses•Cellulitis•Rosacea-like lesions•panniculitis

Case 13

Female 85. Recurrent urinary tract infections, and rash over fingers and dorsal thumb.

The best diagnosis is:

A. Pyodermatitis /Pyostomatitis vegetans

B. Neutrophilic dermatosis of the dorsal hands

C. Squamous cell carcinoma

D. Atypical mycobacterial infection (M.chelonae)