What is the cause of eosinophilia and erythema nodosum?

From the Guidelines

Eosinophilia and erythema nodosum are related conditions that require a thorough evaluation to identify the underlying cause, with helminth infections being a common cause in returning travelers and migrants, as noted in studies such as 1 and 1. When these conditions occur together, it is essential to consider various etiologies, including:

• Medication reactions
• Infections (e.g., streptococcal, tuberculosis, fungal)
• Inflammatory bowel disease
• Sarcoidosis
• Certain malignancies
• Helminth infections, which are common in returning travelers and migrants, with rates varying from 14% to 64% 1 Management involves treating the underlying cause while providing symptomatic relief. For erythema nodosum, treatment options include:
• NSAIDs like ibuprofen (400-800mg three times daily) or naproxen (500mg twice daily) for pain and inflammation
• Bed rest, leg elevation, and cool compresses for additional comfort
• Potassium iodide solution (300-900mg daily in divided doses) for persistent cases
• A short course of oral prednisone (20-40mg daily for 2-4 weeks with gradual tapering) for severe symptoms It is crucial to consider non-infective causes, particularly if the eosinophilia is persistent, as noted in 1. The prognosis is generally good, with most cases resolving within 3-6 weeks once the underlying cause is addressed, though recurrence is possible if the primary condition remains untreated, highlighting the importance of thorough evaluation and treatment, as emphasized in 1 and 1.

From the FDA Drug Label

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) has been reported in patients taking NSAIDs such as ibuprofen tablets. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling Other clinical manifestations may include hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis. Sometimes symptoms of DRESS may resemble an acute viral infection. Eosinophilia is often present. Serious Skin Reactions NSAIDs, including ibuprofen tablets can cause serious skin adverse reactions such as exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. NSAIDs can also cause fixed drug eruption (FDE). FDE may present as a more severe variant known as generalized bullous fixed drug eruption (GBFDE), which can be life-threatening

• Eosinophilia and erythema nodosum are potential symptoms of DRESS and serious skin reactions associated with ibuprofen tablets.
• The presence of eosinophilia is often seen in DRESS, and skin rash or other signs of hypersensitivity may indicate a serious skin reaction.
• If such signs or symptoms are present, discontinue ibuprofen tablets and evaluate the patient immediately 2.

From the Research

Eosinophilia and Erythema Nodosum

• Eosinophilia is a condition characterized by an elevated count of eosinophils in the blood, which can be caused by various factors, including infections, allergic reactions, and certain medications 3.
• Erythema nodosum is a type of skin inflammation that is often associated with eosinophilia, and is characterized by the formation of painful nodules on the skin, typically on the lower legs 4, 5, 6.
• The exact cause of erythema nodosum is often unknown, but it is thought to be a hypersensitivity reaction to various antigenic stimuli, including infections, medications, and systemic diseases 4, 5, 6.

Treatment and Management

• Treatment of eosinophilia often involves addressing the underlying cause, and in some cases, medications such as albendazole may be effective in reducing eosinophil counts 7.
• Treatment of erythema nodosum typically involves symptomatic relief, such as nonsteroidal anti-inflammatory drugs (NSAIDs), and in some cases, systemic steroids may be used, although their use is not always recommended 5, 6.
• It is essential to identify and address any underlying triggers or diseases that may be contributing to the development of erythema nodosum, as treatment of the underlying cause can help to resolve the condition 4, 5, 6.

Diagnosis and Diagnostic Algorithm

• Diagnosis of erythema nodosum involves a combination of clinical evaluation, laboratory tests, and instrumental examinations to identify any underlying trigger disease 4, 5, 6.
• A diagnostic algorithm has been proposed to optimize the initial work-up and management of erythema nodosum, which includes an initial assessment of core symptoms, diagnostic work-up, differential diagnosis, and recommended therapies 4.