Resident Spots and Corrects a Cellulitis Misdiagnosis

Bran T., an internal medicine resident at University of Toronto, shares how VisualDx helped him spot and correct a cellulitis misdiagnosis.

“As an internal medicine resident, I see lots of cutaneous findings on the ward. VisualDx helps me solve a lot of these common skin mysteries. For example, I once saw a patient with ‘bilateral leg cellulitis’ not responsive to antibiotics, and with a little research, I was able to use VisualDx to diagnose panniculitis instead.”

What is panniculitis?

Panniculitis is a collective term for a group of inflammatory diseases involving subcutaneous fat. The panniculitides are subdivided histologically based on the location of the predominant amount of inflammation: in the intralobular septa or within the fat lobule itself. A mixture of patterns may also be seen (septal and lobular). Most share a common presentation of tender dermal or subcutaneous nodules, papules, or plaques. They all may be mistaken for cellulitis. Erythema nodosum (EN) is by far the most common type of panniculitis and one of few mainly involving the septa (septal panniculitis).

What should we be aware of when making a diagnosis?

• The lesions of EN never ulcerate, unlike those of many other types of panniculitis.
• Lupus panniculitis is not limited to patients with lupus.
• A disproportionate number of the lesions of pancreatic panniculitis may be seen in the decubitus areas.
• Trauma may exacerbate or induce the lesions of ?₁-antitrypsin deficiency panniculitis.

How can we treat this?

Spontaneous resolution occurs in most cases of EN. Treat any identified underlying cause of the condition. Bed rest, wet compresses, limb elevation, and NSAIDs may be helpful.

Colchicine has been successful, as has hydroxychloroquine. Intralesional corticosteroids have also been of some benefit. Applying topical corticosteroids with Saran wrap occlusion at night may help to reduce inflammation. Systemic corticosteroids have been used on rare occasion. Isolated case reports have touted the success of the following treatments: dapsone, erythromycin, infliximab, and mycophenolate mofetil.