CME CE
CASE #1
Dermatology Clinic
Lupus profundus
Histopathologic examination of an incisional biopsy from the woman’s arm lesion revealed an inf lammatory infi ltrate of the subcutis in a lobular pattern with moderate hyalinization and calcification. The diagnosis of lupus erythematosus profudus (LEP), also known as lupus panniculitis, was made based on the clinical and histologic findings. LEP, a rare variant in the clinical spectrum of lupus erythematosus (LE), accounts for 1% to 3% of all LE cases, and involves inflammation of subcutaneous fat.1,2 Kaposi first described the condition in 1883 as subcutaneous nodules in patients with SLE.3 Irgang coined the term LEP in 1940 and suggested that LEP was a unique skin finding in LE.4 LEP is now believed to represent a distinct variant of LE, as it may occur in the setting of SLE, in association with such other cutaneous forms of LE as discoid LE (DLE); in conjunction with other autoimmune processes; or, rarely, as an isolated skin finding without an underlying condition.5 According to Wu et al., the incidence of LEP is 2% to 10% in SLE patients and 33% to 70% in DLE patients. Women aged 30 to 60 years are most commonly affected, although LEP has been described in children.2 Recent data suggest that the presence of LEP in a patient with SLE may be predictive of a less severe course.3,6 Lesions of LEP commonly present as indurated and firm, tender, or asymptomatic nodules. At times, the lesions develop as sharply defi ned plaques that arise in crops or appear singly.5 The overlying epidermis is frequently normal in appearance; however, fi ndings of DLE with erythema, atrophy, scaling, ulcerations, follicular plugging, or telangiectasias may be present.5,7 In adults, lesions have a predilection for the proximal upper extremities; the face is more commonly affected in children.7,8 Other frequently affected sites in all patients include the buttocks, chest, breasts, and scalp.5,8 Lesions on the legs are unusual and a useful clinical clue that helps distinguish LEP from other forms of panniculitis.5 Healing of lesions can occur spontaneously or after treatment and often results in atrophic, depressed, and disfiguring scars.5 The pathophysiology of LEP is poorly understood; however, immune complex deposition, as well as T-cell mediated infl ammation, have been implicated.6 Some
studies suggest that LEP is associated with previous trauma and/or injections.9 The differential diagnosis of LEP includes a variety of panniculitides and conditions that affect the deep dermis, such as erythema nodosum, erythema induratum, lupus tumidus, thrombophlebitis, cold panniculitis, deep morphea, and pancreatic fat necrosis.5 In addition, DLE, WeberChristian disease, Jessner’s lymphocytic infi ltrate, sarcoidosis, dermatomyositis, and subcutaneous panniculitis-like T-cell lymphoma (SPTL) can each be clinically confused with LEP. The diagnosis of LEP is made based on clinicalpathologic correlation because there is no pathognomonic clinical, pathologic, or laboratory fi nding diagnostic for LEP. SPTL is the most significant of the diagnoses to correctly identify. Although SPTL usually has more systemic symptoms, the pathologic findings may be identical to those of LEP.7 Immunohistochemistry and molecular studies may be necessary to distinguish the two conditions.9 For diagnosis, adequate subcutaneous tissue must be obtained and submitted for histologic evaluation.10 A punch biopsy is readily obtainable in most office settings and may provide an appropriate specimen. However, the size of the specimen obtained is limited with a punch biopsy, and the amount of fat removed for analysis may not be sufficient. An incisional biopsy allows more subcutaneous tissue to be removed for study and thus may be preferable.10 Serologic studies have little role in the diagnosis of LEP because such studies are frequently normal and, even when abnormal, offer too little consistency to be of diagnostic value.7 Elevated ANA, anti-dsDNA, and rheumatoid factor titers have been described; other reported abnormalities include lymphopenia, anemia, transaminitis, and low complement levels, as well as elevated C-reactive protein and sedimentation.5-7 A deficiency in complement C4 has been repeatedly reported and may be of some significance.7 LEP exhibits a chronic and relapsing course and is often difficult to treat.1 The morbidity of the condition is attributable to lesional pain and disfigurement, both of which can be significant.6 Treatment is effective only if implemented during the active, inflammatory phase of the disease; it is ineffective after scarring and atrophy have occurred.1 While there are currently no FDA-approved medications to treat LEP, there are treatment regimens supported by evidence-based medicine.1 Although the role of UV light in exacerbating the disease is controversial, patients should be advised to routinely use a broad-spectrum sunscreen.8 Topical steroids can be tried alone or in combination with other modalities, but the depth
74 THE CLINICAL ADVISOR • APRIL 2013 • www.ClinicalAdvisor.com