Signs and Symptoms
- Tender erythematous nodules symmetrically distributed on extensor surface of lower legs
- Lesions occasionally occur on fingers, hand s, arms, calves, and thighs
- In bedridden patients, dependent areas may be involved
- Fever, malaise, leukocytosis, arthralgias, arthritis, and unilateral or bilateral hilar adenopathy with any form of the disease
History
- General symptoms may precede or accompany the rash:
- Fever
- General malaise
- Polyarthralgias
- GI symptoms with EN may be a marker for:
- Inflammatory bowel disease
- Bacterial gastroenteritis
- Pancreatitis
- Behçet disease
- A history of travel is important, as there are regional variations in etiology
Physical Exam
- A careful exam is important, as underlying etiology varies by region
- Lesions are most common on the pretibial area but may occur on the thigh, upper extremities, neck and , rarely, the face
- Absence of lesions on the lower extremities is atypical
- Lesions do not ulcerate
- Lower-extremity edema may occur
- Adenopathy should be evaluated
Essential Workup
Careful history and physical exam directed at detecting precipitating cause
Diagnostic Tests & Interpretation
Lab
- CBC
- Throat culture/ASO titer
- ESR
- Appropriate chemistry tests
- Liver function tests
- Serologies for coccidioidomycosis in endemic regions
- TB skin testing in endemic regions
Imaging
CXR: Hilar adenopathy may be evidence of sarcoidosis, coccidioidomycosis, TB, or other fungal infections
Diagnostic Procedures/Surgery
- Definitive diagnosis made by deep elliptical biopsy and histopathologic evaluation (punch biopsy may be inadequate)
- Usually indicated for atypical cases or when TB is being considered
Differential Diagnosis
- EN migrans and chronic EN
- Any type of panniculitis can resemble EN
- Differences can be determined histopathologically
- Other disorders include:
- Nodular vasculitis
- Migratory thrombophlebitis
- Superficial varicose thrombophlebitis
- Scleroderma
- Systemic lupus erythematosus
- α1-antitrypsin deficiency
- Behçet syndrome
- Lipodystrophies
- Leukemic infiltration of fat
- Panniculitis associated with steroid use, cold, and infection
Pediatric Considerations |
- Rare in children, streptococcal pharyngitis is the most likely etiology
- Catscratch disease should be considered
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Prehospital
Maintain universal precautions
Initial Stabilization/Therapy
Airway, breathing, and circulation (ABCs); IV, oxygen, monitoring as appropriate
ED Treatment/Procedures
- Treatment should be directed at underlying disease
- Supportive therapies include rest, limb elevation, and analgesics
- Corticosteroids and potassium iodide may hasten resolution of symptoms
- Systemic corticosteroids are contraindicated in the presence of certain underlying infections such as TB or coccidioidomycosis, which may disseminate with their use
- Potassium iodide is contraindicated in hyperthyroid states and pregnancy
Medication
- Aspirin: 650 mg PO q4-6h p.r.n (peds: contraindicated)
- Ibuprofen: 400-800 mg PO q8h (peds: 5-10 mg/kg PO q6-8h)
- Naproxen: 250-500 mg PO q12h (peds: 5-7 mg/kg PO q12h)
- Indomethacin: 25-50 mg PO q8h
- Potassium iodide/SSKI (used for resistant disease; contraindicated in hyperthyroidism and pregnancy): 360-900 mg PO daily divided q8h for 3-4 wk
- Systemic corticosteroids (prednisone): 40 mg/d PO; duration determined by primary physician
First Line
- Rest/supportive care
- Limb elevation
- NSAIDs
- Treatment of underlying disease
Disposition
Admission Criteria
Dictated by the severity of symptoms and the etiologic agent
Discharge Criteria
- Nontoxic patients, able to take PO fluids without difficulty
- Scheduled follow-up should be arranged
Issues for Referral
- EN is usually self-limited and resolves in 3-6 wk
- Atypical cases may need excisional biopsy
- Steroid and potassium therapy needs primary physician monitoring
- Refractory or recurrent cases need dermatology referral
- Pregnant patients may require obstetric consultation for management considerations
Follow-up Recommendations
- Follow-up to assess for resolution with primary care physician or dermatologist
- Evaluation of underlying etiology may require specialist referral