| Erythema nodosum | Young women, 2nd to 4th decades | Infections (commonly streptococcal), medications, malignancies (leukemias, lymphomas) | Acute onset; symmetric, tender, nodules & plaques Affecting anterior lower extremities Fever, fatigue, arthralgias, arthritis, headache, no ulceration, no atrophy, no scarring | Septal Panniculitis No vasculitis Neutrophils (early), Meischer granulomas (late) | Bed rest, aspirin, NSAIDs SSKI, 2-10 drops thrice daily Colchicine Corticosteroids (rarely indicated) |
| Erythema induratum | Young/middle-aged women | Venous insufficiency, obesity Infectious etiology: MTB, hepatitides B, C | Erythematous SQ nodules on lower extremities May affect calves, anterolateral leg Tenderness, ulceration, scarring Protracted course, with recurrent episodes 3-6 weeks duration | Lobular, often with vasculitis (90%). Early central necrosis of adipocytes; neutrophilic infiltrate In older lesions, epithelioid histiocytes, multinucleated giant cells | If MTB testing is positive, full course of multidrug therapy Treat underlying cause SSKI, NSAIDs, colchicine, antimalarials, corticosteroids, gold Bed rest Pentoxifylline, compression |
| Lipodermatosclerosis (sclerosing panniculitis, hypodermitis sclerodermiformis, chronic panniculitis with lipomembranous changes, sclerotic atrophic cellulitis, venous stasis panniculitis) | Overweight women older than 40 years | Venous insufficiency Obesity Systemic sclerosis Pulmonary Infarction Hypertension | Indurated, woody plaques on lower extremities, with acute & chronic changes (most commonly, anteromedial calf area) Intense pain is the most frequent symptom Stage: acute inflammatory Chronic fibrosis Inverted champagne bottle | Stasis changes Lobular panniculitis No vasculitis Ischemic necrosis at center Thickened, fibrotic septa, atrophy of subcutaneous fat Membranocystic changes | Compression therapy is the major recommended treatment (30-40 mm Hg) Stanozolol: to decrease pain, erythema, induration Pentoxifylline, horse chestnut seed extract, oxerutins, flavonoid fraction Weight loss |
| Infectious panniculitis | — | Wide variety of bacteria, fungi, parasites, viruses Either primarily inoculated, or hematogenous Staphylococcus aureus panniculitis with juvenile diabetes Panniculitis of mycetoma, chromoblastomycosis, sporotrichosis | Erythematous plaques, nodules, abscess with purulent discharge (fluctuant/abscess-type lesions) Most commonly on legs and feet Upper extremities, trunk, face may be involved | Mostly lobular panniculitis, but with a mixed pattern Pattern dependent on whether infection was inoculation related or hematogenous Neutrophilic infiltrate | Depends on the known organisms |
| α1-Antitrypsin panniculitis | Most common in 30-60 years of age groups MM: most common phenotype (normal AAT) ZZ: 10%-15% of N levels; associated with >60% of cases | Pulmonary and hepatic disease (emphysema in COPD, cirrhosis, hepatocellular CA), highest risk ZZ phenotype Panniculitis uncommon in AAT deficiency | Painful erythematous nodules and plaques Cellulitis, fluctuant abscess type Most common ... |