Purpureocillium lilacinum is a saprophytic fungus that exhibits a particular affinity for ocular structures. Pastor et al. [4] conducted a comprehensive review of P.lilacinum infections, and among 119 reports spanning from 1964 to 2004, 51.3% corresponded to ocular mycosis. Key risk factors identified included intraocular lens implantation (32,8%), non-surgical trauma (20%) and ophthalmic surgery (10%). Notably, a significant number of patients had received corticosteroid treatment at the onset of ocular symptoms since these cases of endophthalmitis are frequently misdiagnosed. The outcomes revealed that 25% of cases experienced vision loss and 38% resulted in enucleation.

There is a limited number of reported cases of P. lilacinum in the literature. Guo et al. [5] reported a case of a 54-year-old immunocompetent woman initially misdiagnosed with uveitis, treated for two years with antibiotics and glucocorticoids. Upon suspicion of fungal endophthalmitis, she underwent two vitrectomies and antifungal therapy, achieving a final visual acuity of luminous perception. P. lilacinum was identified in surgical cultures. The patient had no significant medical history but had experienced a minor corneal injury two years before while caring for her grandchild, suggesting a potential entry point for the fungus and subsequent slow, progressive growth leading to chronic inflammation.

A recent case report highlighted P. lilacinum endophthalmitis in a 4-year-old immunocompetent child with no discernible risk factors. Initially misdiagnosed as panuveitis, the child’s visual acuity was ultimately diminished to no luminous perception despite surgery and antifungal treatment [6]. .

In line with the cases discussed, in our scenario, the patient exhibited no underlying systemic conditions and had not undergone immunosuppressive therapy prior the onset of the situation. Notably, there was no recent history of trauma to the left eye and the cataract and vitrectomy surgery were performed 10 years’ prior presentation.

The sole pertinent recent event was the surgery conducted on the fellow eye four months earlier, prompting suspicion of sympathetic ophthalmia (SO). Initial treatment for SO involves corticosteroids, while alternative immunomodulators and immunosuppresors have been traditionally contemplated for refractory and relapsing cases when tapering down corticosteroid treatment [7]. Nevertheless, for conditions such as SO, the early initiation of these medications has proven effective in improving long-term visual outcomes and minimizing ocular complications [8]. Jonas et al. documented a case of SO that did not respond to systemic steroids and immunosuppresors, and proposed intravitreal triamcinolone acetonide as an alternative treatment, as it proved successful in their case [9]. Regarding the anti-TNF therapy, Hiyama et al. reported two cases where Adalimumab demonstrated effectiveness as treatment for patients with a partial response to systemic corticosteroids and other immunosuppressors [10].

In our case, the left eye exhibited + 4 cells in anterior chamber despite treatment with 1 mg/kg/day of prednisone and 20 mg weekly methotrexate for nearly a month. Consequently, the decision was made to use intravitreal Dexamethasone as a bridge therapy before initiating Adalimumab. In hindsight, the unilateral nature of the ocular presentation and the absence of even a partial response to maximum corticosteroid treatment should have been considered as indicators that the condition was not primarily an inflammatory non-infectious process, as initially presumed. However, since no surgery, traumatic event or other systemic signs nor symptoms were evoked during extensive interrogation, infectious disease was not suspected.

An alternative hypothesis could be the onset of an exogenous fungal endophthalmitis following the intravitreal Dexamethasone implantation, indicated by the appearance of purulent material one week after the procedure. However, given the extended duration of ocular inflammation and the absence of response to previous treatments, the likelier scenario suggests fungal endophthalmitis from the beginning of the picture. Additionally, there are no documented cases of fungal endophthalmitis following intravitreal dexamethasone injection.

During the first surgery, purulent retrolental and vitreous material were extracted and sent for analysis. Vitreous cultures were conducted, revealing fungal growth four days post-surgery, with identification of P. Lilacinum one week after the procedure, delaying treatment modification and optimization. The implementation of KOH calcofluor white staining would have enabled direct visualization of the fungus and facilitated the initiation of antifungal treatment much sooner. Regrettably, obtaining this staining in our facility is exceedingly difficult.

Throughout the patient’s hospitalization, collaborative monitoring with the Infectious Diseases department revealed no other infectious focus that could account for endogenous endophthalmitis. After ruling out endogenous origins, the primary suspicion focused on an unnoticed microtrauma in a middle-aged patient or a gradually progressing infection, where inoculation might have occurred a decade prior during cataract and vitrectomy surgery. The likelihood of an undetected trauma seems minimal, as the patient did not report any symptoms such as conjunctival bleeding, abscess, trauma, or pain in the preceding years, and had not sought medical consultation. Conversely, it is acknowledged that fungal aetiologies can be insidious, often taking years to manifest. The presence of an inoculum in the lens could clarify the initial symptoms observed, with most of the inflammation predominantly located around the lens.

This case pose diagnostic challenges, as the absence of recent trauma, surgery or systemic condition can misleadingly exclude endophthalmitis from the differential diagnosis. The patient had been receiving systemic and topical corticosteroid treatment for the past two months, and during his stay at our hospital he underwent an intravitreal dexamethasone injection. This intervention may have exacerbated the situation by inducing local immunosuppression, thereby fostering the progression of the infection and the growth of the fungus, ultimately worsening the prognosis.