Cutaneous protothecosis in a solid organ transplanted patient

35-year-old woman, with a history of cretinism and chronic idney disease secondary to congenital urological pathology, eceived a kidney transplant at the age of 30. At 5 years, ue to graft rejection, she required a new transplant and as started on prednisone 20 mg/day, tacrolimus 16 mg/day, nd mycophenolate mofetil 250 mg every 8 hours. During her admission for bacteremia secondary to uriary tract infection, an erythematous plaque with diffuse orders and discrete asymptomatic superficial scaling was bserved on the anterior and lateral sides of her left leg Figs. 1 and 2). Laboratory investigations showed leukoytes of 4900 mm3 with a relative neutrophilia of 94%. rterial and venous Doppler ultrasound of the left lower imb showed lymphedema and increased echogenicity of the ubcutaneous tissue. PET-CT revealed an increase in the ensity of the subcutaneous cellular tissue, accompanied y an inflammatory process. Skin biopsy was performed for istopathology and culture of bacteria, mycobacteria, and ungi. The first presented large, rounded structures, with ultiple cytoplasmic septa, some with a morula-like appearnce, and numerous sporangia with internal septa forming ndospores (Fig. 3 and 4). In culture, creamy white colonies ere observed, some rough with depressed centers, compaible with Prototheca spp. (Fig. 5). Systemic treatment with liposomal Amphotericin B 00 mg/day was started, with an improvement of the skin esions. Fourteen days later, he has switched to itraconaole 200 mg every 8 hours for 3 days and then continued at 00 mg every 12 hours. It evolved in a torpid way with parial improvement and intermittent worsening. At 9 months, new skin culture was performed where the sensitivity f Prototheca was verified, and treatment was changed to uconazole 200 mg every 12 hours and minocycline 100 mg very 12 hours. Ultimately, she developed septic shock related to a uriary tract infection caused by carbapenemase-producing lebsiella pneumonia. Antibiotic treatment was adminis-

Asymmetry of the lower limbs due to an increase in the circumference of the left leg associated with erythema on its anterior region tered, but despite this, the patient developed multi-organ failure and died.
Protothecosis is a rare infection caused by algae of the species Prototheca spp. Within the species of the Prototheca genus, Prototheca wickerhamii and zopfii are the ones that most frequently affect immunocompromised hosts. 1,2 Prototheca infection ranges from indolent and localized skin involvement, soft tissue infection, olecranon bursitis in immunocompetent patients, to devastating disseminated infection with algemia and visceral infiltration with high mortality in immunocompromised hosts due to transplant, diabetes, HIV, and hematologic diseases. 2,3 The cutaneous form represents the most frequent manifestation (3 out of 4 patients). The lesions usually appear in areas exposed LETTER -TROPICAL/INFECTIOUS AND PARASITIC DERMATOLOGY   In culture, creamy white colonies were observed, some rough with depressed centers, compatible with Prototheca spp to traumatic implantation. It usually presents with poorly defined erythematous plaques, although less frequently it can manifest with nodular, pustular, warty, and ulcerated lesions.
Diagnosis is made by clinical suspicion, detection of characteristic structures in skin cultures, and microscopic examination. The definitive diagnosis of infection is usually based on the morphological identification of the organisms in culture preparations in wet slides and/or direct identification in tissue samples as in the reported case. 1---4 Its prognosis is good in almost 70% of cases. On the other hand, when it presents in a disseminated form, it has a worse prognosis, with high mortality. 1,5 The most commonly used medications are antifungals, including amphotericin B and systemic azoles. Amphotericin B is currently the first-line treatment in disseminated cases and in patients with severe underlying diseases or immunosuppression. 6---9 In conclusion, protothecosis is an infrequent infection with nonspecific skin manifestations, so in the presence of plaques, nodules, ulcerated or warty lesions in immunosuppressed patients, a skin biopsy should be performed for culture and histopathology to detect infectious agents. The initiation of adequate treatment prevents the progression of the disease. 5---10 Financial support None declared.

Authors' contributions
Anama Di Prinzio: The study concept and design; writing of the manuscript.
Marina Ruf: The study concept and design; intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases.
Ana C. Torre: Data collection, or analysis and interpretation of data.

Conflicts of interest
None declared.

Dear Editor,
Treponema pallidum, subspecies pallidum, is the causative agent of syphilis. Syphilis can be transmitted through sexual contact, blood transfusion, solid organ transplantation, and from mother to child. 1,2 The rising incidence of syphilis is a global public health problem. 3 Despite the large number A 24-year-old man presented to the emergency room in July 2020 with a painless genital ulcer for the preceding 20 days (Fig. 1A). Subsequently, multiple non-pruritic and painless erythematous papules with peripheral desquamation appeared. These papules had a symmetrical distribution, located on the trunk (Fig. 1B), upper limbs, and palmoplantar region ( Fig. 2A). He also had odynophagia and right peripheral facial palsy (Fig. 2B). He underwent kidney transplantation 18 months prior to the presentation. Immunosuppression included tacrolimus, sodium mycophenolate, and prednisone. He reported being heterosexual and denied sexual intercourse in the 3 months prior to presentation, or any previous episodes of syphilis. The serum treponemal Chemiluminescence Immunoassay (CLIA) test of the recipient before KTx was nonreactive (Table 1), as was