Discussion:
Severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) is very contagious, that why it spread rapidly around the world since the end of 2019 causing the most recent respiratory pandemic in our century. History that might reveal exposure risk for diagnosed cases as well clinical manifestations plays an important role in the suspicion and thus diagnosis cases and controlling infection spread. Diagnosis confirmation is mainly via reverse transcriptase chain reaction (RT-PCR) though it has 30% false negative rate. Clinical manifestations might vary widely. However, the most common ones are fever, fatigue, headache, and myalgia. Gastrointestinal symptoms were considered less common[1]. Other atypical presentation like anosmia (Loss of smell), Agnosia (Loss of taste) were reported before[3].
The impact of coronavirus on pregnant women is not clear till today. However, some studies consider pregnancy as vulnerable state and viral infections might increase morbidity and mortality in the mother as well her fetus yet no evidence to our date that pregnancy increases COVID-19 susceptibility and risk of COVID-19 complications[1]. During pregnancy the symptoms were as described among non-pregnant patients. However, our patient has smooth course of infection and normal delivery without complication. Cacosmia was the only persistent symptoms that cause her nausea and few times vomiting during the second and third trimester which obviously affected her psychologically and nutrition.
Recent European study observed the ENT presentation of COVID-19 and found that olfactory and gustatory dysfunction are quite common with olfactory dysfunction occurring in 85.6% and gustatory dysfunction in 88% [2]. Another study showed that olfactory loss or anosmia occurs in 39% following upper respiratory infections with a return to normal rate that varies depending on multiple factors like the patient age, gender and if the baseline disorder is hyposmia or anosmia [4]. Thus, anosmia was suggested to be one of the diagnostic criteria especially in the presence of other symptoms, and most of the patients that were included of this study described that changing on taste and smell happened after other symptoms rather from the beginning. [5,6].However, Cacosmia which happened in our patient was note prescribed in the previously published studies.
Olfactory disturbances are classified into three categories: first, Hyposmia and anosmia which mean decreased sensitivity. Second, odorant stimulation disorders where there is a distortion in the perceived odor (Troposmia), and third, smelling hallucination where the odor is mostly unpleasant (phantosmia), unpleasant phantosmia sometimes called cacosmia. Usually the distortions on the smell is the most upsetting symptoms to the patients and remarkably affects their quality of life among these disturbances. Etiology behind this disorder is not clearly defined but it can be categorized into central and peripheral. Central etiologies or combination of both[7].
To the best of our knowledge, no previously published articles about cacosmia, thought other olfactory disorders like hyposmia and anosmia have been clearly described. Our patient had the gustatory and olfactory symptoms from the beginning. The persistent of hyposmia and cacosmia mainly was very irritant to her, giving her unpleasant feeling during her second and third trimester and causing persistent nausea. By excluding other possible diagnosis, persistent of complain after delivery, not responding to specific treatments, all of these factors made us correlate the patient complain to COVID-19 especially on the absence of similar episodes before the infection. We believe that physician should be aware of the ENT presentation of COVID-19 including ageusia and anosmia as well considering cacosmia in COVID-19 patients. Whether pregnancy has a role on the prolongation of this atypical symptoms or not is something that needs further research. Physician as well should take into account the implication of cacosmia on the pregnant women due to the physiological impact and the affect on the nutrition which might indeed affect the pregnancy.