A42-year-old female with a past medical history of COPD and ovarian cysts presented with painful sores on the bilateral dorsal hands of 11 days duration. The lesions started as tiny blisters and rapidly progressed to ulcers. A similar lesion, which resolved spontaneously, appeared about one year prior. She admitted to a two-week period of nausea, but denied fever, upper respiratory infection, hematuria, or any change in appetite or bowel habits. Initially, the patient was treated with oral and topical antibiotics by her primary care physician with no relief.

Upon examination, the patient was found to have multiple violaceous plaques with central ulceration and a pustular surface on the bilateral dorsal hands (Figure 1). The posterior neck revealed four erythematous scaly plaques. Furthermore, mild submandibular adenopathy with right-sided tenderness was present. Laboratory studies revealed leukocytosis with a white blood cell count of 13.1 x 103/μl, erythrocyte sedimentation rate of 62, and C-reactive protein of 20.2. Serum electrolytes, liver, and renal function test were normal. Urinalysis showed albumin level of 46.3.

A wound culture and gram stain were negative. The histopathologic report of a specimen from a lesion on the patient's dorsal hand was described as follows:
A dense superficial and deep perivascular and interstitial mixed-cell infiltrate composed mostly of neutrophils and nuclear “dust.” The papillary dermis is edematous. An ulceration with scale crust is seen. PAS was negative for fungal hyphae. This description is consistent with Sweet's Syndrome, ulcerated.

Based on the patient's history, physical examination, along with the laboratory and histopathological findings, the diagnosis of neutrophilic dermatosis of the hands (NDH), a subset of Sweet's syndrome, was made. The patient was provided with topical clobetasol and a referral to oncology for further work up. The patient was lost to follow-up post discovery of bilateral lung tumors.

Discussion
Sweet's syndrome (SS) or acute febrile neutrophilic dermatosis is part of a collection of inflammatory diseases known as the neutrophilic dermatoses. SS was first described by Robert Douglas Sweet in 1964.1 SS most commonly involves middle-aged women. Patients may complain of flu-like symptoms prior to the dermatologic eruption. Skin exam reveals inflammatory papules that coalesce into irregular plaques, often forming an annular lesion. Leukocytosis and polymorphonuclear leukocytes over 10,000mm3 is a common finding but may not always be present.1 Histologic features include papillary dermal edema, intense neutrophilic infiltrate, and leukocytoclastic vasculitis.2 The differential diagnosis of SS includes pyoderma gangrenosum, erythema multiforme, urticarial vasculitis, erythema elevatum diutinum, panniculitis, halogenoderma, pyoderma, septic vasculitis, deep fungal infection, mycobacterial infection, leishmaniasis, lymphoma cutis, and metastatic carcinoma.3

Diagnosis of SS involves the presence of two major criteria including the abrupt onset of typical cutaneous lesions and histopathology consistent with SS.2 The minor criteria include antecedent fever or infection, accompanying fever, arthralgia, conjunctivitis, or underlying malignancy, leukocytosis, and a good response to systemic corticosteroids and no response to antibiotics.2 The therapeutic gold standard for SS is systemic corticosteroids.3 Other first-line oral systemic agents are potassium iodide and colchicines.3

Second-line oral systemic agents include indomethacin, clofazimine, cyclosporine, and dapsone.3 Occasionally the lesions of SS may resolve spontaneously with no therapeutic intervention. Localized lesions can be treated with high potency topical corticosteroids and intralesional corticosteroids.3

Neutrophilic dermatosis of the hands (NDH) is a localized variant of Sweet's syndrome.2 Strutton et al was the first to describe violaceous papulonodules on the radial aspect of the dorsal hands.4 Five years later it was given the name neutrophilic dermatosis of the dorsal hands by Galaria.2,4,5 Since then there have been a little over 60 cases reported, and “dorsal” was removed from the name.6 In the majority of cases, the lesions are located entirely on the dorsal aspect of the hands, but there have been reports of NDH involving the lateral and palmar surface.

The literature suggest that atypical pyoderma gangrenosum, SS, and pustular vasculitis of the hands are variations of a single disease entity designated NDH of the dorsal hands.2 NDH has been associated with a number of conditions, which are listed in Table 1. With hematologic malignancies or solid tumors present in 10 percent of reported cases, it is imperative to a patient's health that s/he be fully worked up for any possible malignant associations or underlying systemic diseases. Diagnosis and treatment of NDH is identical to that of classical SS.

Conclusion
Neutrophilic dermatosis of the dorsal hands is an uncommon variant of Sweet's syndrome that often goes unrecognized. Awareness of this unique presentation is important for a variety of reasons. The lesions of NDH are frequently misdiagnosed as an infectious process and treated incorrectly. This is exemplified by a case reported in which a patient was misdiagnosed with gangrene, and the digit was amputated. The lesion reappeared at the base of the amputation and was diagnosed as NDH clinically by a dermatologist and verified by histopathological analysis of the amputated digit.11 This patient was found to have an underlying myelodysplastic syndrome. In conclusion, prompt recognition of NDH may prevent superfluous antibiotic treatment, unwarranted surgery, and expedite the work up for serious underlying conditions as exemplified by the presented case.