Causes

Extrinsic eosinophilic syndrome

Loeffler syndrome- it’s a hypersensitivity response to an ingested or inhaled antigen from food, medication, or an infectious agent

• Parasitic infections- Round worm and hook worm infestation, Microfilarials, Schistosomiasis and Strongyloidiasis
• Tropical pulmonary eosinophilia- Wuchereria bancrofti or Brugia malayi infestations leading to lymphatic filariasis
• Fungal infections- Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic response to Aspergillus fungus
• Bronchocentric granulomatosis
• Asthma can cause pulmonary eosinophilia
• Drugs like sulfonamides, Nonsteroidal anti-inflammatory drugs, L-tryptophan, antidepressants, and contraceptives

Intrinsic eosinophilic syndrome

• Acute eosinophilic pneumonia
• Chronic eosinophilic pneumonia
• Idiopathic hypereosinophilic syndrome
• Churg-Strauss syndrome
• Eosinophilic granuloma- pulmonary histiocytosis X or Langerhans cell granulomatosis

Signs and symptoms

Toxic products released from eosinophils causes damage to respiratory epithelium and causes bronchus constriction.

• Chest pain
• Dry cough
• Wheezing
• Low grade fever
• Shortness of breathe
• Rashes
• Weight loss and fatigue
• Pruritus dermatitis- itching
• Hurried respiratory rate

Tests and diagnosis

• Complete blood count with absolute eosinophil count (AEC). Normal blood AEC is as high as 250/µL.
• Sputum examination, broncho alveolar lavage, and bronchoscopy
• Stool for ova and cyst
• IgE levels- Levels of less than 1000 ng/mL are usually seen in association with asthma and low-intensity infections.
• IgE levels more than 2000 ng/ml are typically associated ABPA and parasitic infections.
• Chest X-ray and CT chest
• Pulmonary function test

Treatment

• Supplemental oxygen of 5-6 lts
• Bronchodilators – Salbutamol, Albuterol as injectable and inhalational route
• Inhaled steroids is also helpful
• Rarely systemic steroids (Prednisone and Methyl prednisolone) are required
• Remove the potential offending medications or ingested substances.
• Antiparasitic agents- Albendazole, Mebendazole, Praziquantel, and Ivermectin
• Antifungal agents- Itracanazole, Flucanazole and Amphotericin -B