Saw cerebral toxoplasmosis today so here my quick refresher 🧵
🎙Toxoplasmosis:
🦠- protozoal infection caused by Toxoplasma gondii
Transmission - food borne (🥩🥬), zoonotic (🐈), congenital, blood transfusion, organ transplantation
🔎- in immunocompetent pts, it’s usually asymptomatic (maybe flu like illness or chorioretinitis), lifelong
In immunocompromised pts are at risk for reactivation of toxo
👇🏼
💡HIV w/ CD4 < 200
💡SOT
‼️Make sure to screen all organ donors & recipients
⚡️Highest risk of infection
is D+/R-. Most common in 🫀
⚡️Commonly in the first 6 mo post transplant & in those not on Bactrim ppx
📌Pneumonitis - similar to PCP
📌🧠 mass lesions or encephalitis ➡️ CSF might have ⬆️ protein & mononuclear pleocytosis
📌Myocarditis (commonly mistaken for 🫀allograft
failure)
🔬- serology (IgM, IgG), PCR, tissue
IgM -, IgG + ➡️ no acute infection
IgM + ➡️ acute infection
IgM & IgG + ➡️ ⁉️since IgM can stay + for up to 12 mo
⚡️PCR is more sensitive for acute infection ➡️ 🩸, CSF, BAL
💊 - PO pyrimethamine + sulfadiazine + leucovorin
Immunocompetent: only with severe or prolonged
symptoms ➡️ 2-4 wks
Ocular disease: 6 wks
Immunocompromised: 6 wks induction ➡️ chronic suppression w/ the same 💊 or Bactrim
👇🏼
💡💊 work on proliferative tachyzoite form but not the encysted parasite
⚡️Serial PCR testing to
monitor response can be useful
❓Sulfadiazine can cause what kind of adverse drug reaction?
Answer: renal obstruction. Due to crystallized sulfadiazine similar to acyclovir or atazanavir
❓Why do we add leucovorin to the pyrimethamine + sulfadiazine regimen?
Comment 👇🏼
• • •
Missing some Tweet in this thread? You can try to
force a refresh
📟 8 YO admitted w/ flushing, an urticaria rash on face & torso, and itching
His mom says the rash occurred within an hr of him eating a tuna sandwich. He complained of a spicy taste & had perioral burning causing her to seek medical help
❓What is the most likely diagnosis?
Answer: Scombroid poisoning
👇🏼
🎙Fish Poisoning Syndromes:
🚨Scombroid:
⚡️commonly misdiagnosed as a seafood allergy so be 👀
Due to the incorrect storage of 🐟 (above 4C) ➡️ bacterial overgrowth & ⬆️ histamine (by bacterial enzyme called histidine decarboxylase)
👇🏼
📟 14 YO boy from Ghana with 🤒 & malaise reports a 5 week history of mulriple skin lesions, which are show below. The lesions on his legs are painful & pruritic. He says multiple kids from his school have them too
🧪- VDRL & FTA-ABS +
❓What organism most likely caused this?
Answer: Treponema pallidum subsp pertenue
🎙Endemic Treponematoes:
🚨Yaws:
🦠- Treponema pallidum subsp pertenue
🗺- Africa, Asia, Latin America, Pacific Islands
Incubation ⏲- 3 wks
Transmission - auto inoculation, close contact with infected lesion
🔎- 🧒🏻👧🏻
Primary Stage -
📟 A farmer from the Dominican Republic is here in the US visiting family & presents with a swollen foot that has been progressing over the past 8 years
📸 of his R foot along with biopsy of lesion
❓What is the mostly likely organism?
Answer: Madurella mycetomatis
🎙Cutaneous Fungal/Mold Infections:
🚨Madurella mycetomatis: Eumycetoma or “Madura foot”
🔎- traumatic inoculation ➡️ chronic nodular lesions w/ sinus tracts w/ macroscopic grains ➡️ 🦴 Evolve over yrs
🔬- grain w/ numerous hyphae
👇🏼
This is fungal