History and exam

Key diagnostic factors

Reported in approximately 77% of patients.[138] In one case series, only 44% of patients had a fever on presentation, but it developed in 89% of patients after hospitalisation.[702] The course may be prolonged and intermittent, and some patients may have chills/rigors. The prevalence of fever is higher in adults compared with children; approximately 54% of children do not exhibit fever as an initial presenting symptom.[703] In children, fever may be absent or brief and rapidly resolving.[704]

Reported in approximately 68% of patients.[138] The cough is usually dry; however, a productive cough has been reported in some patients. Can persist for weeks or months after infection.[705]

Reported in approximately 38% of patients.[138] Median time from onset of symptoms to development of dyspnoea is 5 to 8 days.[45][46][706] May last weeks after initial onset of symptoms. Wheeze has been reported in 17% of patients.[707]

Presence of anosmia and/or ageusia may be useful as a red flag for diagnosis.[576] Olfactory dysfunction (anosmia/hyposmia) has been reported in approximately 41% of patients, and gustatory dysfunction (ageusia/dysgeusia) has been reported in approximately 35% of patients.[138] Prevalence appears to be higher in European studies.[708] May be an early symptom before the onset of other symptoms, or may be the only symptom in patients with mild to moderate illness.[709] Prevalence of anosmia/ageusia presenting before other symptoms was 13% to 73%, at the same time as other symptoms was 14% to 39%, and after other symptoms was 27% to 49%.[710] Persistent anosmia has an excellent prognosis with nearly complete recovery at 1 year.[711] Anosmia or hyposmia is significantly associated with an enhanced risk of testing positive for COVID-19, and is a good predictor of infection.[712] Many drugs are associated with taste and smell changes (e.g., antibiotics, ACE inhibitors) and should be considered in the differential diagnosis.[713] Smell and taste dysfunction are common in children.[714]

Other diagnostic factors

Reported in approximately 30% of patients.[138] Patients may also report malaise. Fatigue and exhaustion may be extreme and protracted, even in patients with mild disease.

Reported in approximately 17% (myalgia) and 11% (arthralgia) of patients.[707] Arthritis has been reported rarely.[715]

Reported in approximately 18% of patients.[138]

Reported in approximately 22.9% of patients.[611]

Reported in 20% of patients. The weighted pooled prevalence of specific symptoms is as follows: loss of appetite 22.3%; diarrhoea 2.4%; nausea/vomiting 9%; and abdominal pain 6.2%. Gastrointestinal symptoms appear to be more prevalent outside of China, although this may be due to increased awareness and reporting of these symptoms as the pandemic progressed.[716] Gastrointestinal symptoms are not associated with an increased likelihood for testing positive for COVID-19; however, anorexia and diarrhoea, when combined with loss of smell/taste and fever, were 99% specific for COVID-19 infection in one prospective case-control study.[717] The presence of gastrointestinal symptoms may be a predictor of progression to severe disease.[718][719] However, the presence of these symptoms does not appear to affect intensive care unit admission rate or mortality.[720] The presence of diarrhoea has been associated with a severe clinical course in children.[596] Haematochezia has been reported.[721]

Reported in approximately 16% of patients.[138] Usually presents early in the clinical course.

Reported in approximately 25% of patients. Headache is twice as prevalent in COVID-19 patients compared with patients with non-COVID-19 viral respiratory tract infections.[722]

Reported in approximately 11% of patients.[707]

Confusion has been reported in approximately 11% of patients.[707]

The overall prevalence of delirium is 24.3%, with an increased prevalence in adults >65 years of age (28%). Delirium has been associated with a 3-fold increase in mortality.[723] Benzodiazepine use and the lack of family visitation (virtual or in-person) have been identified as risk factors for delirium.[724]

The pooled prevalence of anxiety, depression, and insomnia is 15.2%, 16%, and 23.9%, respectively.[725]

Altered mental status was as common in younger hospitalised patients (<60 years) as it was in older patients in one study.[726]

Reported in 11% of patients. The most common ocular symptoms include dry eye or foreign body sensation (16%), redness (13.3%), tearing (12.8%), itching (12.6%), eye pain (9.6%), and discharge (8.8%). Conjunctivitis was the most common ocular disease in patients with ocular manifestations (88.8%).[727] Most symptoms are mild and last for 4 to 14 days with no complications. Prodromal symptoms occur in 12.5% of patients.[728] Mild ocular symptoms (e.g., conjunctival discharge, eye rubbing, conjunctival congestion) were reported in 22.7% of children in one cross-sectional study. Children with systemic symptoms were more likely to develop ocular symptoms.[729] Retinal complications that may lead to vision loss have also been reported.[730]

Rhinorrhoea has been reported in approximately 8% of patients, and nasal congestion has been reported in approximately 5% of patients.[707]

Sudden sensorineural hearing loss, tinnitus, and rotatory vertigo have been reported in 7.6%, 14.8%, and 7.2% of patients, respectively. Otalgia has also been reported.[731]

Reported in approximately 7% of patients.[707] May indicate pneumonia.

The pooled prevalence of overall cutaneous lesions is 5.7%. The most common symptoms are a viral exanthem-like presentation (4.2%), maculopapular rash (3.8%), and vesiculobullous lesions (1.7%). Other manifestations include urticaria, chilblain-like lesions, livedo reticularis, and finger/toe gangrene.[732][733] In the UK COVID Symptom Study, 17% of respondents reported rash as the first symptom of disease, and 21% of respondents reported rash as the only clinical sign.[734] Cutaneous signs may be the only, or the first, presenting sign.[735] Cutaneous symptoms have been reported in children.[736] It is unclear whether skin lesions are from viral infection, systemic consequences of the infection, or drugs the patient may be on. Further data is required to better understand cutaneous involvement and whether there is a causal relationship. A prospective case series in adolescents found that chilblain-like lesions are not associated with systemic or localised SARS-CoV-2 infection.[737] Severe and potential life-threatening mucocutaneous dermatological manifestations have also been reported.[738]

British Association of Dermatologists: Covid-19 skin patterns external link opens in a new window

There is emerging evidence that patients may rarely have signs, symptoms, and radiological and laboratory features indicative of involvement of the lower urinary tract and male genital system. This may include scrotal discomfort, swelling, or pain (acute orchitis, epididymitis, or epididymo-orchitis), low-flow priapism, impaired spermatogenesis, bladder haemorrhage, acute urinary retention, and worsening of existing lower urinary tract symptoms (including exacerbation of benign prostatic hyperplasia). Further research is required.[739][740]

Reported in approximately 2% of patients.[707] May be a symptom of pulmonary embolism.[741]

May indicate pneumonia.

May be present in patients with acute respiratory distress.

May be present in patients with acute respiratory distress.

May be present in patients with acute respiratory distress.

May be present in patients with acute respiratory distress.

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