Vascular Pythiosis in a Thalassemic Patient

Abstract

Pythium insidiosum is a fungus that causes disease in both animals and humans. Human pythiosis is an emerging disease in the tropical, subtropical, and temperate regions of the world, occurring in localized and systemic or vascular forms. Most patients with arterial pythiosis have an underlying hemoglobinopathy, such as thalassemia. A case is presented of a thalassemic horse stable worker who developed an ulcerative cutaneous lesion on the lower left leg followed by progressive ascending involvement of the arteries of that extremity with a necrotizing arteritis with aneurysm formation. P. insidiosum was not isolated from the ulcer by culture or wet potassium hydroxide preparations but was diagnosed by histopathologic study of a biopsy. P. insidiosum infection was quickly confirmed by immunoblot method, aiding in preoperative decision making. Many systemic antibiotics or antimycotics have not been effective in the treatment of systemic pythiosis, and radical surgical removal of all infected tissue is the only method to ensure patient survival. An orally administered saturated solution of potassium iodide, amphotericin B-oral solution, and terbinafine has succeeded only in the cutaneous form but had no favorable effect on vascular pythiosis. It is likely that immunotherapy, successfully used in animal pythiosis, may be beneficial in the treatment of human vascular pythiosis.

Outbreak of Pythium Keratitis During Rainy Season

“…1,20,21 From a major review study in Thailand, 59 of 86 human pythiosis patients (69%) had underlying thalassemia hemoglobinopathy: the majority had vascular pythiosis. 1,21 Interestingly, most ocular pythiosis patients are relatively healthy individuals.…”

“…1,20,21 From a major review study in Thailand, 59 of 86 human pythiosis patients (69%) had underlying thalassemia hemoglobinopathy: the majority had vascular pythiosis. 1,21 Interestingly, most ocular pythiosis patients are relatively healthy individuals. 1,20 In our study, only 1 patient had the thalassemic trait (hemoglobin E trait) and 1 had hemoglobin E disease (normally asymptomatic), whereas the other 2 patients had no underlying hematologic disease.…”

The emerging epidemiology of mould infections in developing countries

“…Pythium insidiosum, an opportunistic oomycete (pseudofungi), has been reported almost exclusively from Thailand [60][61][62][63]. It is frequently isolated from irrigation water and reservoirs in Thailand, and is endemic in its agricultural regions [61,62].…”

“…It is frequently isolated from irrigation water and reservoirs in Thailand, and is endemic in its agricultural regions [61,62]. Pythiosis manifests either in a localized form, such as corneal ulcers or chronic cutaneous lesions, or in a systemic or vascular form [61,62] on the extremities in individuals with underlying haemoglobinopathies [61,62].…”

Diagnosis and Treatment of Pythium Insidiosum Corneal Ulcer in a Chinese Child: A Case Report and Literature Review

“…The organism usually presents in 2 forms: one is the hyphae characterized by right-angle branching or broad filaments, and the other is the aquatic motile biflagellate zoospore, which is the infective propagule and only presents in aquatic environments [5]. Clinical presentation of human pythiosis can be classified into 4 types: subcutaneous [6], vascular [7–11], ocular [3,12,13], and systemic [4,14,15]. Consistent with other forms, ocular pythiosis has been proved to have extremely poor prognosis.…”