Discussion
The onset of delusion of infestation several years after the diagnosis may pose a challenge in causal linkage within the natural cause of HIV/AIDS because of the multifactorial nature of Ekbom syndrome. Nevertheless, the diagnosis of a psychotic disorder (Ekbom syndrome) due to another medical condition is met as per DSM-V criteria. Ekbom Syndrome may develop following dementia or other organic diseases(8), and the presence of HIV significantly increase the risk(9).
The ritualistic skin picking and subsequent lesions may suggest skin excoriation disorder. However, the presence of an unshakable conviction of being infected by living things supports the diagnosis of delusion of infestations, specifically Ekbom syndrome(9)and no other variant known as Morgellons disease of which an individual believes to be infested with inanimate objects like hairs, strands or fibers(10)
Although there was no overt CNS opportunistic infection, the objective assessment suggested CNS involvement manifesting as HIV-associated neurocognitive disorders. While cognitive assessment with MoCA showed no significant decline, the assessment with IHDS showed significant deficit, particularly in motor and psychomotor functioning, attributable to slow information processing speed as one of the most common cognitive impairments in HIV Associated Neurocognitive Disorder(HAND)(11). This suggests the specificity and strength of IHDS in screening for subcortical cognitive deficits, which are typical in HIV(12). Cognitive impairment (CI) in patients living with HIV is commonly reported. As the population ages, the problem becomes more significant; even with sufficient antiviral medication, milder forms of CI still exist(13). Low CD4 counts (200 cells/mm3), prolonged HIV infection, and advanced age are risk factors for HIV Associated Dementia (HAD)(14). Generally, using ARTs improves the overall clinical outcome; however, the association with neuropsychiatric manifestation has also been observed. Antiretroviral medications such as Efavirenz used for our patient are linked to neurocognitive impairment (15) and also psychotic symptoms, including Ekbom syndrome(16).
Perhaps the most intriguing observation is the onset of depressive symptoms soon after the resolution of psychotic symptoms as a condition that may be referred to as post psychotic depression(17). Albeit having a five-year history of psychosis, a first-episode psychosis(FEP) has a notably higher incidence rate (50%) of post-psychotic depression compared to non-first-episode psychotic patients(18). Also, treatment for FEP within the first year is linked to increased risk, with approximately half of the patients experiencing depression at the beginning of their treatment, and more than a third continues to have it at the one-year follow-up(19).
Until recently, pimozide, a first-generation antipsychotic, was considered the treatment of choice for delusional infestation. Because of newer-generation antipsychotics with better safety profiles and equal efficacy, pimozide has lost relevance(4). The patient used haloperidol, which is readily available and has a relatively safer cardio-metabolic profile than the newer generation antipsychotics(20).
The prognosis of this patient is somewhat guarded by her cardiovascular and HIV/AIDS intermediate outcome. Her advanced age significantly risks cardiovascular complications in addition to her HIV status. Prevention of the progression of HIV/AIDS and cerebrovascular event is crucial for favorable medical and psychiatric outcomes. Her strong family support is essential for close to follow-up and treatment adherence.