A very high eosinophil count with fatigue, muscle pain, and periorbital edema points to a tissue-invasive helminth infection, most classically Trichinella spiralis (trichinosis). The parasite is acquired from eating undercooked pork, and its larvae migrate into and encyst within striated muscles, provoking a strong eosinophilic inflammatory response. The muscle inflammation causes the patient’s fatigue and muscle pain, while inflammation around facial muscles can produce periorbital edema. Eosinophilia can be markedly elevated, as in this scenario. Diagnosis is supported by serology or detecting larvae in muscle tissue, and treatment typically involves antiparasitic drugs such as albendazole or mebendazole, with corticosteroids if inflammation is more severe. Other listed conditions—hydatid cyst disease, Chagas disease, and cysticercosis—can involve eosinophils or tissue lesions, but their typical presentations do not match the combination of migratory muscle involvement, very high eosinophils, and periorbital edema seen with trichinosis.