1. Introduction
oronaviruses are a large family of viruses that are known to cause respiratory infections in humans [1]. SARS-CoV-2 is a new type of this family that was initiated in late 2019 and its related disease is known as COVID-19 [4]. Symptoms such as fever, cough, fatigue, muscle aches, joint pain, and shortness of breath have been reported as common symptoms of this virus [4, 7]. In addition to these symptoms, SARS-CoV-2 also affects various organs of the body such as the gastrointestinal tract, nervous system, skin, olfactory system, cardiovascular system, liver, kidneys and eyes. This study aims to provide comprehensive information on extrapulmonary complications of COVID-19 in order to develop control and intervention strategies.
2. Materials and Methods
This is a narrative review study. The literature search was conducted in databases such as PubMed, Scopus, ScienceDirect, and Google Scholar on studies published in English from December 2019 to May 10, 2020 using following keywords:COVID-19, SARS-CoV-2, olfactory dysfunction, loss of taste, gastrointestinal disease, skin manifestations, cardiovascular disease, kidney disease, liver disease, neurological disorder, eye disease, thyroid disease, and diabetes complications. In the initial search, 1105 articles were yielded. After removing duplicates and evaluating their titles and abstracts, 32 articles were selected for the review.
3. Results
SARS-CoV-2 can cause neurological manifestations from relatively specific symptoms such as anosmia, ageusia, myopathy and stroke to nonspecific symptoms such as headache, dizziness, loss of consciousness or seizures [30]. Studies on COVID-19 patients have also reported common gastrointestinal symptoms, such as diarrhea, nausea, and vomiting [14]. Another reported rare symptom is a skin rash in the form of erythematosus, chronic urticaria, and chickenpox-like blisters that occur without itching or slight itching in the trunk [16]. Acute heart failure has been reported as the most common heart disease in COVID-19 cases. Other diseases are myocarditis and cardiac arrest [20]. Recent reports indicate acute renal failure in patients with COVID-19, and hypothetical mechanisms have been proposed, including sepsis leading to cytokine storm or direct cell damage by SARS-CoV-2 [23]. Liver damage in these patients may be directly related to viral infection of the liver cells, immune-mediated inflammation such as cytokine storm, and hypoxia caused by pneumonia [28, 29]. There is a two-way relationship between COVID-19 and diabetes; diabetes is associated with an increased risk of severe COVID-19. On the other hand, sudden diabetes and severe metabolic complications of diabetes, such as diabetic ketoacidosis, for which very high doses of insulin are needed, have also been observed in patients with COVID-19 [37].
4. Discussion and Conclusion
The results of this review study showed that the complications of COVID-19 are not limited to the lungs, but can go beyond and affect other organs. There have been numerous reports of systemic consequences of COVID-19. Awareness of the effects of SARS-CoV-2 infection outside the airways can be important in the management of patients with underlying diseases. Due to the novelty of COVID-19, information in this field is constantly updated and increased, and the mechanisms associated with the complications are not yet fully clear. Further studies should be performed on the various damages caused by COVID-19 to determine the exact relationship between the pathogenesis, prognosis and severity of the disease.

Ethical Considerations
Compliance with ethical guidelines
This article is a meta-analysis with no human or animal sample. 

Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors. 

Authors' contributions
Conceptualization, writing – original draft: Somayeh Shatizadeh Malekshahi; Research: Somayeh Shatizadeh Malekshahi, Ameneh Omidi and Parsa Veisi; Edited and writing – original draft: Somayeh Shatizadeh Malekshahi and Ameneh Omidi.

Conflicts of interest
The authors declare no conflict of interest.

Acknowledgements
The authors would like to thank all colleagues in the Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University.


References

1. Su S, Wong G, Shi W, Liu J, Lai ACK, Zhou J, et al. Epidemiology, genetic recombination, and pathogenesis of coronaviruses. Trends Microbiol. 2016; 24(6):490-502. [DOI:10.1016/j.tim.2016.03.003]
2. Channappanavar R, Perlman S. Pathogenic human coronavirus infections:Causes and consequences of cytokine storm and immunopathology. Semin Immunopathol. 2017; 39(5):529-39. [DOI:10.1007/s00281-017-0629-x]
3. Jiang F, Deng L, Zhang L, Cai Y, Cheung CW, Xia Z. Review of the clinical characteristics of coronavirus disease 2019 (COVID-19). J Gen Intern Med. 2020; 35(5):1545-49. [DOI:10.1007/s11606-020-05762-w] [PMCID]
4. Lai CC, Shih TP, Ko WC, Tang HJ, Hsueh PR. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and corona virus disease-2019 (COVID-19):The epidemic and the challenges. Int J Antimicrob Agents. 2020; 55(3):105924. [DOI:10.1016/j.ijantimicag.2020.105924]
5. Park SE. Epidemiology, virology, and clinical features of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2; Coronavirus disease-19). Clin Exp Pediatr. 2020; 63(4):119-4. [DOI:10.3345/cep.2020.00493]
6. Zimmermann P, Curtis N. Coronavirus infections in children including COVID-19. Pediatr Infect Dis J. 2020; 39(5):355-8. [DOI:10.1097/INF.0000000000002660]
7. Ganji A, Mosayebi G, Khaki M, Ghazavi A. [A review of the 2019 novel Coronavirus (Covid-19):Immunopathogenesis, molecular biology and clinical aspects (Persian)]. J Arak Uni Med Sci. 2020; 23(1):8-21. [DOI:10.32598/JAMS.23.1.51.5]
8. Welge-Lüssen A,Wolfensberger M. Olfactory disorders following upper respiratory tract infections, in Taste and Smell. Adv Otorhinolaryngol. 2006; 63:125-32. [DOI:10.1159/000093758]
9. Machado C, Gutierrez JV. Anosmia and ageusia as initial or unique symptoms after sars-cov-2 virus infection. Preprints. 2020. [DOI:10.20944/preprints202004.0272.v1]
10. Goncalves S, Goldstein BJ. Pathophysiology of olfactory disorders and potential treatment strategies. Curr Otorhinolaryngol Rep. 2016; 4(2):115-21. [DOI:10.1007/s40136-016-0113-5]
11. Fodoulian L, Tuberosa J, Rossier D, Landis BN, Carleton A, Rodriguez I. SARS-CoV-2 receptor and entry genes are expressed by sustentacular cells in the human olfactory neuroepithelium. BioRxiv. 2020; Preprint. [DOI:10.1101/2020.03.31.013268]
12. Baig AM, Khaleeq A, Ali U, Syeda H. Evidence of the COVID-19 virus targeting the CNS:Tissue distribution, host–virus interaction, and proposed neurotropic mechanisms. ACS Chem Neurosci. 2020; 11(7):995-8. [DOI:10.1021/acschemneuro.0c00122]
13. Bagheri SHR, Asghari AM, Farhadi M, Shamshiri AR, Kabir A, Kamrava SK, et al, Coincidence of COVID-19 epidemic and olfactory dysfunction outbreak. Med J Islam Repub Iran. 2020; 34(1):446-52. [DOI:10.34171/mjiri.34.62]
14. Wang L, Gao YH, Lou LL, Zhang GJ. The clinical dynamics of 18 cases of COVID-19 outside of Wuhan, China. Eur Respir J. 2020; 55(4):2000398. [DOI:10.1183/13993003.00398-2020]
15. Tian Y, Rong L, Nian W, He Y. Gastrointestinal features in COVID-19 and the possibility of faecal transmission. Aliment Pharmacol Ther. 2020; 51(9):843-51. [DOI:10.1111/apt.15731]
16. Recalcati S. Cutaneous manifestations in COVID-19: A first perspective. J Eur Acad Dermatol Venereol. 2020; 34(5):e212-3. [DOI:10.1111/jdv.16387].
17. Sachdeva M, Gianotti R, Shah M, Bradanini L, Tosi D, Veraldi S, et al. Cutaneous manifestations of COVID-19: Report of three cases and a review of literature. J Dermatol Sci. 2020; 98(2):75-81. [DOI:10.1016/j.jdermsci.2020.04.011]
18. Manalo IF, Smith MK, Cheeley J, Jacobs R. A dermatologic manifestation of COVID-19: Transient livedo reticularis. J Am Acad Dermatol. 2020; 83(2):700. [DOI:10.1016/j.jaad.2020.04.018]
19. Bansal M. Cardiovascular disease and COVID-19. Diabetes Metab Syndr. 2020; 14(3):247-50. [DOI:10.1016/j.dsx.2020.03.013] [PMCID]
20. Rizzo P, Vieceli Dalla Sega F, Fortini F, Marracino L, Rapezzi C, Ferrari R. COVID-19 in the heart and the lungs: Could we “Notch” the inflammatory storm? Basic Res Cardiol. 2020; 115(3):31. [DOI:10.1007/s00395-020-0791-5]
21. Tan W, Aboulhosn J. The cardiovascular burden of coronavirus disease 2019 (COVID-19) with a focus on congenital heart disease. Int J Cardiol. 2020; 309:70-7. [DOI:10.1016/j.ijcard.2020.03.063]
22. Zheng YY, Ma YT, Zhang JY, Xie X. COVID-19 and the cardiovascular system. Nat Rev Cardiol. 2020; 17(5):259-60. [DOI:10.1038/s41569-020-0360-5] [PMCID]
23. Naicker S, Yang CW, Hwang SJ, Liu BC, Chen JH, Jha V. The Novel Coronavirus 2019 epidemic and kidneys. Kidney Int. 2020; 97(5):824-8. [DOI:10.1016/j.kint.2020.03.001]
24. Wang D, Hu B, Hu C, Zhu F, Liu X, Zhang J, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus–infected pneumonia in Wuhan, China. JAMA. 2020; 323(11):1061-9. [DOI:10.1001/jama.2020.1585].
25. Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: A descriptive study. Lancet. 2020; 395(10223):507-3. [DOI:10.1016/S0140-6736(20)30211-7]
26. Li Z, Wu M, Yao J, Guo J, Liao X, Song S, et al. Caution on Kidney Dysfunctions of 2019-nCoV Patients. MedRxiv. 2020; Preprint. [DOI: 10.1101/2020.02.08.20021212].
27. Cheng Y, Luo R, Wang K, Zhang M, Wang Z, Dong L, et al. Kidney impairment is associated with in-hospital death of COVID-19 patients. Kidney Int. 2020; 97(5):829-38. [DOI:10.1016/j.kint.2020.03.005] [PMCID]
28. Zhang C, Shi L, Wang FS. Liver injury in COVID-19:Management and challenges. Lancet Gastroenterol Hepatol. 2020; 5(5):428-30. [DOI:10.1016/S2468-1253(20)30057-1]
29. Sun J, Aghemo A, Forner A, Valenti L. COVID-19 and liver disease. Liver Int. 2020; 40(6):1278-81. [DOI:10.1111/liv.14470]
30. Pleasure SJ, Green AJ, Josephson SA. The spectrum of neurologic disease in the severe acute respiratory syndrome coronavirus 2 pandemic infection:neurologists move to the frontlines. JAMA Neurol. 2020; 77(6):679-80. [DOI:10.1001/jamaneurol.2020.1065]
31. Wu P, Duan F, Luo C, Liu Q, Qu X, Liang L, et al. Characteristics of ocular findings of patients with coronavirus disease 2019 (COVID-19) in Hubei Province, China. JAMA Ophthalmol. 2020; 138(5):575-8. [DOI:10.1001/jamaophthalmol.2020.1291].
32. Xia J, Tong J, Liu M, Shen Y, Guo D. Evaluation of coronavirus in tears and conjunctival secretions of patients with SARS-CoV-2 infection. J Med Virol. 2020; 92(6):589-94. [DOI:10.1002/jmv.25725]
33. Chen M, Zhou W, Xu W. Thyroid function analysis in 50 patients with COVID-19:A retrospective study. Thyroid. 2020; 31(1):8-11. [DOI:10.1089/thy.2020.0363].
34. Brancatella A, Ricci D, Viola N, Sgro D, Santini F, Latrofa F. Subacute thyroiditis after SARS-CoV-2 infection. J Clin Endocrinol Metab. 2020; 105(7):dgaa276. [DOI:10.1210/clinem/dgaa276]
35. Ruggeri RM, Campenni A, Siracusa M, Frazzetto G, Gullo D. Subacute thyroiditis in a patient infected with SARS-COV-2: An endocrine complication linked to the COVID-19 pandemic. Hormones (Athens). 2020. [DOI:10.1007/s42000-020-00230-w] [PMCID]
36. Ippolito S, Dentali F, Tanda ML. SARS-CoV-2:A potential trigger for subacute thyroiditis? Insights from a case report. J Endocrinol Invest. 2020; 43(8):1171-2 [DOI:10.1007/s40618-020-01312-7]
37. Chee YJ, Huey Ng SJ, Yeoh E. Reply to comments on Letter to the Editor–Diabetic ketoacidosis precipitated by Covid-19 in a patient with newly diagnosed diabetes mellitus. Diabetes Res Clin Pract. 2020; 166:108305. [DOI:10.1016/j.diabres.2020.108305]
38. Li J, Wang X, Chen J, Zue X, Zhang H, Deng A. COVID-19 infection may cause ketosis and ketoacidosis. Diabetes Obes Metab. 2020; 22(10):1935-41. [DOI:10.1111/dom.14057]
39. Rubino F, Amiel SA, Zimmet P, Alberti G, Bornstein S, Eckel RH, et al. New-Onset Diabetes in Covid-19. N Engl J Med. 2020; 383(8):789-90. [DOI:10.1056/NEJMc2018688]
40. Altable M. de la Serna JM. Cerebrovascular disease in COVID-19:Is There a higher risk of stroke? Brain Behav Immun Health. 2020; 6:100092. [DOI:10.1016/j.bbih.2020.100092] [PMCID]
41. Mao L, Jin H, Wang M, Hu Y, Chen S, He Q, et al. Neurologic manifestations of hospitalized patients with coronavirus disease 2019 in Wuhan, China. JAMA Neurol 2020; 77(6):683-90. [DOI:10.1001/jamaneurol.2020.1127]
42. Reddy ST, Garg T, Shah C, Nascimento FA, Imran R, Kan P, et al. Cerebrovascular disease in patients with covid-19:A review of the literature and case series. Case Reports in Neurol. 2020; 12(2):199-209. [DOI:10.1159/000508958] [PMCID]