In toxoplasma retinochoroiditis, the 'headlight in the fog' appearance on fundoscopy refers to:
- A Optic disc oedema surrounded by flame haemorrhages
- B A bright yellow retinal lesion adjacent to a white chorioretinal scar, with overlying vitritis ✓
- C Macular star formation with papillitis
- D White-centred haemorrhages (Roth spots) in the posterior pole
Explanation
The 'headlight in the fog' or 'satellite lesion' appearance in toxoplasma retinochoroiditis describes a bright white-yellow active retinal focus adjacent to a pigmented chorioretinal scar from a prior episode, surrounded by dense vitritis (the 'fog'). Toxoplasma gondii (obligate intracellular parasite) reactivates from tissue cysts within the retina. The treatment regimen (Daraprim protocol: pyrimethamine + sulfadiazine + folinic acid, with systemic steroids) is indicated for lesions threatening the macula, disc, papillomacular bundle, or causing severe vitritis. Clindamycin plus TMP-SMX are alternatives.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.