Neutrophilic dermatosis of the dorsal hands: an emerging entity

Abstract

Editor Neutrophilic dermatoses are a collection of diseases of which Sweet's syndrome is a protoptype. Clinical features of Sweet's syndrome include acute onset of painful erthematous papules, plaques or nodules accompanied by fever and peripheral neutrophil leucocytosis. Histologically, a dense neutrophilic infiltrate without evidence of primary vasculitis is found.1 An acral form of Sweet's syndrome is recognized and now termed neutrophilic dermatosis of the dorsal hands (NDDH).2 We report here two cases of NDDH. The first patient was an 80-year-old Chinese woman with newly diagnosed myelodysplastic syndrome. She developed a bulla on the dorsum of her right hand and a purplish, bruise-like patch over the dorsum of her left hand. Both areas were previous sites of intravenous (IV) cannulation. Within a few days, the lesions on both hands expanded into large haemorrhagic, oedematous plaques (Fig. 1). Her C-reactive protein and erythrocyte sedimentation rate were markedly raised. A skin biopsy revealed dermal oedema and an infiltrate of neutrophils, lymphocytes with extravasated red blood cells. Tissue cultures were negative. Based on the clinical and histological findings, NDDH was diagnosed. High-dose prednisolone and cyclosporine failed to control the skin lesions. She was subsequently given IV immunoglobulin for refractory thrombocytopaenia. With this regimen, the plaques finally began to resolve. Unfortunately, she subsequently died from nosocomial pneumonia. Haemorrhagic, purpuric and necrotic plaque with an overlying flaccid bulla and surrounding erythema and oedema over the dorsum of the right hand. The second case was a 78-year-old Chinese woman with peripheral vascular disease who underwent above-knee amputation for right leg gangrene. Two weeks postoperatively, she developed a wound infection. Concurrently, she developed indurated violaceous plaques with pustules over the dorsum of both hands. The plaques were located over IV cannulation sites. Skin biopsy confirmed a neutrophilic dermatosis. Systemic steroid was withheld in view of the concurrent infection, and she was treated with topical 0.1% betamethasone valerate ointment. Her wound infection was successfully treated with IV antibiotics and her rashes resolved completely. NDDH is a localized form of Sweet's syndrome. It has been previously called ‘pustular vasculitis’, ‘atypical pyoderma gangrenosum’ and ‘bullous pyoderma gangrenosum’.3, 4 Sweet's syndrome is frequently associated with haematological malignancies, solid tumours and inflammatory bowel disease.5 A similar pattern is seen in NDDH. We collated and reviewed 55 cases of NDDH that has been reported in the literature2, 3, 6-9 (including our two cases) and found that haematological diseases (18%) were most commonly associated with NDDH, followed by ulcerative colitis (11%) and solid tumours (9%). Pathery was present in both of our cases, and this has also been previously reported.2, 6 The pathogenesis of Sweet's syndrome remains unknown. It is thought to be related to an altered immunological state in reaction to bacterial, viral or tumour antigens. It has been theorized that cytokine dysregulation plays a key role in the activation of neutrophils and release of toxic metabolites.10 The management of NDDH is similar to Sweet's syndrome. Majority of cases respond well to systemic corticosteroids.2, 6, 8 Dapsone has been used either alone or in combination with systemic corticosteroids to good effect.2, 8 Other medications that have been used as adjuncts to steroids include cyclosporine, methotrexate, potassium iodide and salazopyrine. Monotherapy with colchicine, minocycline, azathioprine, intralesional triamcinolone, topical steroids, topical tacrolimus have also had anecdotal success.8, 9 The prognosis of NDDH is generally good as the disease is usually readily treatable with corticosteroids or other immune modulating or anti-inflammatory drugs. In some cases, maintenance doses of dapsone, minocycline or colchicine are required to prevent disease recurrence. In conclusion, NDDH can be best understood as a localized variant of Sweet's syndrome. It is commonly associated with an underlying systemic illness and most cases are readily treatable with systemic corticosteroid therapy.