Sweet's Syndrome

A dermatologic emergency; Sweet's syndrome

BACKGROUND

Sweet's syndrome (SS), also known as acute febrile neutrophilic dermatosis, is a rare condition characterized by recurrent erythematous skin lesions. Skin lesions appear as papules, nodules and plaques located on the upper extremity, trunk, neck and face.

CASE REPORT

A 72-year-old male patient presented to the emergency department with a 10-day history of generalized rash, generalized muscle and joint pain and high fever. He had a history of upper respiratory tract infection. He presented with painful erythematous plaques on both lower and upper extremities and the trunk as well as serohemorrhagic bullous lesions on the feet. The laboratory results revealed WBC count of 20.6 × 10³/mm³ (76.9% neutrophils), CRP (c-reactive protein) of 33 mg/L and erythrocyte sedimentation of 110/h. The patient was referred to a dermatologist with prediagnosis of SS due to the presence of typical painful skin lesions, high fever and neutrophilic leukocytosis. A systemic corticosteroid therapy was initiated. The diagnosis for SS was confirmed after the skin biopsy revealed the presence of dense dermal infiltrate of neutrophils and leukocytoclasis in the upper dermis. The patient responded rapidly to corticosteroids and the skin lesions improved.

CONCLUSION

We reported this case as it was a rare life-threatening dermatosis diagnosed in the emergency department, which is generally difficult to diagnose therein, and the skin lesions appeared on the lower extremities.

A not-so-sweet diagnosis - leukocytoclastic vasculitis masquerading as squamous cell carcinoma

Leukocytoclastic vasculitis (LCV) is a rare small-vessel vasculitis characterised by neutrophilic inflammation of post-capillary venules. Incidence varies from 3 to 4.5 per 100 000 people per year. Patients typically present with painful, itchy purpura and erythema, although clinical manifestations can vary making diagnosis a challenge. We report the case of a 75-year-old man with a history of a previously completely excised and grafted squamous cell carcinoma (SCC) on the dorsum of his hand, who presented with an acutely swollen, erythematous and ulcerated lesion adjacent to the graft site. A shave biopsy failed to definitively exclude SCC recurrence. He was referred to the Plastics team who initially suspected Sweet's syndrome but could not rule out SCC recurrence. The patient underwent formal mapping incisional biopsies that later diagnosed LCV. He was managed conservatively and made an excellent recovery. We present clinical photographs and histology to illustrate disease progression. LCV is typically self-limiting with a good overall prognosis, but a minority of patients follow a protracted course, which may require treatment in the form of systemic corticosteroids or colchicine. LCV can only be confirmed histologically. We present this case in order to highlight the importance of adequate tissue biopsy when there is diagnostic uncertainty with an acute dermatosis, particularly in the context of previous skin malignancy.