Progressive Cutaneous Protothecosis

Abstract

The diagnosis of severe progressive cutaneous protothecosis in a 34-year-old woman was made by skin biopsy and culture. Analysis of host defense mechanisms revealed a persistent defect in the ability of the patient's PMN to kill the infecting organism. Specific IgG and IgE antibody was demonstrated. Serum levels of complement and immunoglobulins were normal or elevated. The patient was not anergic and peripheral blood lymphocytes responded to nonspecific mitogens. Treatment with amphotericin B and tetracycline resulted in resolution of skin lesions and negative cultures.

Human Protothecosis

“…Systemic and local predisposing factors can be identified in nearly all patients. Humans with cellular deficiency are at risk for protothecosis (56), and it has been postulated that quantitative (112) and qualitative (15) defects in neutrophil function play an important role in the host defense against Prototheca species (12,24,157). Human polymorphonuclear neutrophils (PMNs) ingest and kill P. wickerhamii.…”

“…Prototheca spp. have been found to colonize the human skin, fingernails, respiratory tract, and digestive system (10,125,133,140,157,163). Up to now, 117 cases of protothecosis have been described in the literature, of which 66% (n ϭ 77), 19% (n ϭ 22), and 15% (n ϭ 18) were associated with cutaneous infection, systemic infection (defined as the presence of Prototheca species in noncontiguous organs), and olecranon bursitis, respectively.…”

“…The most common presentation of cutaneous protothecosis is usually a vesiculobullous and ulcerative lesion with purulent discharge and crusting (142,150,157). However, the spectrum of cutaneous lesions can take various other forms, including erythematous plaques, pustules, papules, nodules, verrucous lesions, pyodermic and herpetiform lesions, vesicles, ulcers, and hypopigmented or atrophic lesions (27,50,56,88,164).…”

“…Synergistic activation of amphotericin B and tetracycline has been observed in vitro (79). Five patients with cutaneous protothecosis received this combination and were successfully treated (52,61,152,157,166). Takaki et al (144) reported induction of secondary resistance during a 3-year period of therapy and clinical failure.…”

Protothecal Tenosynovitis

“…Typical sources of Prototheca species are trees, fresh and salt water, sewage treatment plants, garbage dumps, and household garbage [16]. They can be isolated from skin, feces, or sputum of humans or animals in the absence of clinical manifestations [19]. The pathogenesis of protothecosis is largely unknown, but it is believed Prototheca species infect humans by contact with potential sources or by traumatic inoculation of the algae [8].…”