Panniculitis as the first sign of systemic lupus erythematosus.

Sir,

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease that can affect every organ system of the body. SLE is protean in its manifestations and the skin is one of the target organs most variably affected by the disease, which can yield valuable diagnostic and prognostic information.[1] We describe an interesting case in who panniculitis proved to be the first sign of the SLE. A 30-year-old man presented to the emergency department with a 2-day history of severe pain and swelling of his right thigh without systemic symptoms [Figure 1]. His past medical history, physical examination, and laboratory findings [Figures 2 and 3] were unremarkable except marked erythema and a tender, firm swelling overlying the upper part of right thigh and on the skin over the iliac crest. Initially, deep vein thrombosis was suspected however, Doppler sonography showed nonoccluded femoral vein and finally an inflammatory process was contemplated. With suspicion of bone or skin infection, antibiotics were administered empirically, however, bone scan ruled out osteomyelitis. Skin biopsy of involved area revealed panniculitis. Initial treatment, which was targeted to alleviate symptoms, consisted of elevation of the affected site and the use of anti-inflammatory agents. The patient improved with steroid therapy. At a follow-up visit 1 year later, he had a positive anti-dsDNA titer, which could be interpreted as SLE. Panniculitis is inflammation of subcutaneous adipose tissue and may be a sign of systemic disease.[2] Lupus panniculitis is an unusual variant of lupus erythematosus occurring in 2%–5% of patients. Conversely, 10%–15% of the patients with lupus panniculitis develop SLE. Most of the patients are adults with the age range of 20–60 years. Persistent, firm, well-defined nodules and plaques on face, scalp, breast, arms, thighs, and buttocks characterize this entity which may ulcerate and heal with scarring.[34] Lupus panniculitis is often difficult to diagnose as other form of panniculitis may present similarly. The knowledge of clinical features and histopathology of disease is important because lupus panniculitis may precede SLE (nearly in 50% of cases) by some years.[5]

Figure 1

Showing erythematous swelling over the right iliac crest and upper part of right thigh

Figure 2

Slide (low resolution). Fatty tissue showing fibrin within fibrous septa and containing an infiltrate of mixed inflammatory cells

Figure 3

Slide (high resolution). Infiltrate of lymphocytes and other inflammatory cells surrounding individual adipocytes