Neutrophilic Urticarial Dermatosis as a Presenting Sign of Systemic Lupus Erythematosus

Summary: Systemic lupus erythematosus (SLE) is an autoimmune disease that commonly presents in young women near the third and fourth decade of life, although it can occur in any age, sex, or ethnicity. It can involve multiple systems including joints, kidneys, lungs, and skin. The most well-known cutaneous findings associated with SLE are malar rash, discoid lupus, hair loss, and photosensitivity. This case report highlights an unusual case of neutrophilic urticarial dermatosis as the presenting sign of SLE. A 27-year-old female presented with a 2-month history of rash consisting of well-demarcated, urticarial plaques that began on the head and progressed to the trunk and extremities. The patient described these lesions as burning and stinging in nature. She had recently taken amoxicillin for an inner ear infection, and the rash began soon after. The patient had visited the emergency department multiple times for this rash and received oral prednisone and topical hydrocortisone cream. For the past month, the patient had also developed tongue and facial swelling along with arthralgias. Diagnostic labs revealed low C3, C4, and total complement with positive rheumatoid factor, antinuclear antibodies 1:160, anti-Sjögren’s Syndrome A antibodies, and anti-double stranded DNA antibodies. Urinalysis was significant for hematuria and trace proteins. Punch biopsy was performed and histopathology revealed superficial to deep perivascular, peri-adnexal, and interstitial neutrophil-rich inflammatory infiltrate with extensive karyorrhexis, - findings compatible with neutrophilic urticarial dermatosis. Treatment was begun with oral corticosteroids and patient was started on hydroxychloroquine 200 mg twice daily at the recommendation of rheumatology. Hypocomplement urticarial vasculitis syndrome (HUVS) is characterized by recurrent episodes of painful, persistent urticaria that lasts greater than 24 hours. These lesions often resolve with residual hyperpigmentation and may have associated constitutional symptoms, angioedema, and arthritis. Viral infections and connective tissue diseases, especially SLE and Sjögren’s Syndrome, are known to be associated with HUVS. On histopathology, urticarial vasculitis is defined as a minimum of leukocytoclasia with vessel wall necrosis, with or without fibrinoid deposits, perivascular inflammation, or red blood cell extravasation. It is important to note that patients with hypocomplement are more likely to have systemic involvement and greater disease burden compared to cutaneous-limited disease in those with normal complement levels. While antihistamines can be useful for symptomatic relief of cutaneous lesions, they will not alter disease course. Oral corticosteroids can be effective for disease management, but their duration should be kept to a minimum. Other beneficial treatments reported include dapsone, colchicine, indomethacin, hydroxychloroquine, and mycophenolate mofetil. For recalcitrant hypocomplementemic urticarial vasculitis, rituximab or IVIG may be useful. This case illustrates the need to remain clinically vigilant for underlying connective tissue disorder in a patient presenting with urticarial dermatosis.