Common cold is a term used to describe general symptoms of upper respiratory tract infection including nasal congestion, rhinorrhoea, sneezing, sore throat, and cough. The common cold is usually self-limiting. But symptom severity varies, and it may linger, leading to sinusitis, otitis, laryngitis, tonsillitis, and bacterial infection. Common cold is a burden on family life, health care, and a cause of absence from work and school.1
Rhinovirus is the most common cause of cold. Other causes include adenovirus, respiratory syncytial virus, coronavirus, and influenza (cause of flu). The latter two cause a wide range of symptom severity similar to common cold but also present with systemic flu-like syndrome featuring headache, fever, myalgia, weakness, and anorexia and can lead to significant morbidity and mortality. Viruses have unique pathogenic mechanisms rendering development of a universal treatment for the common cold challenging. Therefore, management of symptoms is currently the best practice clinical approach.1,2
On average, adults have between two and four colds per year while young children have six to eight. The mean duration of colds is seven to 10 days, but some can last for up to three weeks.2
The clinical manifestations result from the body’s immune response rather than the virus itself. The local symptoms of sneezing, nasal congestion, rhinorrhoea, cough, and sore throat are due to bradykinin and prostaglandins acting on blood vessels, glands, and nerves. Sneezing is also linked to histamine and central cholinergic control.2
Patients commonly find nasal congestion and rhinorrhoea the most bothersome symptoms. Cold symptom severity rises rapidly, and peaks within two to three days. But the severity of congestion and rhinorrhoea rises throughout the first week and predominates the tail end of the cold. Rhinorrhoea is initially due to parasympathetic nerve stimulation of nasal glands but is eventually mediated by inflammation causing plasma exudate. Blocked nose is due to congestion of nasal passages from dilatation of veins. This leads to narrowing of the airway, pressure, and sometimes blockade of sinuses and sinusitis. Viscous nasal mucous can clog the restricted airway worsening congestion.1,2 Consequences of this includes difficulty breathing and sleep disruption.3,4
Evidence for nasal decongestant treatment of the common cold
Topical and oral nasal decongestants act on alpha adrenoceptors to constrict nasal veins.5 Cochrane review determined that multiple doses of oral decongestants have a small positive effect on congestion associated with common cold and they are well tolerated.6
Topical decongestants work rapidly (5–10 minutes), as they are applied directly to the mucosa.5 Oral decongestants are slower acting (30–60 minutes), as they first must be absorbed into the systemic circulation.3-5 A small randomised, open label, single dose study found that intranasal oxymetazoline significantly decongested the nasal passages compared to placebo.7 The effect of intranasal decongestants lasts for up to 12 hours (see Figure 1).
Oral and intranasal antihistamines and intranasal corticosteroids are effective for the nasal congestion associated with allergic rhinitis but evidence to support their efficacy in blocked nose due to the common cold is lacking.8
Nasal inhalation containing aromatic oils works quickly to help clear nasal congestion.9 Aromatic rub improves subjective measures of sleep disturbance in adults and children with common cold.10,11 Inhalations, rubs and saline irrigation are recommended for nasal congestion in children.12
Management of nasal congestion
Over-the-counter (OTC) treatment options available for controlling nasal congestion are described in the following table.
FIGURE 1: AXIAL MRI IMAGES SHOWING SEGMENTATION OF THE INFERIOR TURBINATES PRE- AND POST-TREATMENT 7
Safety of nasal decongestants
Oral decongestants have been implicated in adverse cardiovascular outcomes in susceptible patients. Short-term use of over-the-counter doses help to reduce the risk.13 Topical decongestants are well-tolerated, less likely to cause serious adverse effects, and are an option for use in pregnancy. They can cause some local irritation. Overuse of topical decongestants can cause rebound congestion. Their use should be restricted to no more than 3–5 days. They should not be used in children younger than 6 years.14
Pharmacists have a role to play in differentiating between common cold, influenza and coronavirus. The nasal symptoms of common cold are commonly the most bothersome and can be controlled with decongestants. Intranasal decongestants work rapidly and have limited adverse effects. They should not be used in children younger than 6 years, in whom rubs, inhalations and saline irrigation are preferred.
The authors would like to acknowledge the research team at Sir Peter Mansfield Magnetic Resonance Centre at the University of Nottingham for their work in the original collection of the MRI data presented in this article.
1. Heikkinen T, Järvinen A. The common cold. Lancet. 2003;361 (9351):51-9. 2. Eccles R. Mechanisms of symptoms of common cold and flu. In: Eccles R, Weber O, eds. Common cold. Basel: Birkhäuser, 2009. 3. Eccles R. Etiology of the common cold: modulating factors. In: Eccles R, Weber O, eds. Common cold. Basel: Birkhäuser, 2009. 4. Druce HM, Ramsey DL, Karnati S, et al. Topical nasal decongestant oxymetazoline (0.05%) provides relief of nasal symptoms for 12 hours. Rhinology. 2018;56(4):343-50. 5. Eccles R. Over the counter medicines for colds. In: Eccles R, Weber O, eds. Common cold. Basel: Birkhäuser, 2009. 6. Deckx L, De Sutter AI, Guo L, et al. Nasal decongestants in monotherapy for the common cold. Cochrane Database Syst Rev. 2016;10(10):CD009612. Published 2016 Oct 17. 7. Pritchard S, Glover M, Guthrie G, et al. Effectiveness of 0.05% oxymetazoline (Vicks Sinex Micromist®) nasal spray in the treatment of objective nasal congestion demonstrated to 12 h post-administration by magnetic resonance imaging. Pulm Pharmacol Ther. 2014;27(1):121-6. 8. Meltzer EO, Caballero F, Fromer LM, et al. Treatment of congestion in upper respiratory diseases. Int J Gen Med. 2010;3:69-91. 9. Eccles R, Jawad M, Ramsey DL, et al. Efficacy of a topical aromatic rub (Vicks VapoRub®)-speed of action of subjective nasal cooling and relief from nasal congestion. Open J Respir Dis. 2015;5:10-18. 10. Santhi N, Ramsey D, Phillipson G, et al. Efficacy of a topical aromatic rub (Vicks VapoRub®) on effects on self-reported and actigraphically assessed aspects of sleep in common cold patients. Open J Respir Dis. 2017;7:83-101. 11. Paul IM, Beiler JS, King TS, et al. Vapor rub, petrolatum, and no treatment for children with nocturnal cough and cold symptoms. Pediatrics. 2010;126(6):1092-9. 12. Fashner J, Ericson K, Werner S. Treatment of the common cold in children and adults. Am Fam Physician. 2012;86(2):153-9. 13. AMH Online. Oral decongestants. Australian Medicines Handbook. Adelaide: Australian Medicines Handbook Pty Ltd, January 2020 edn. Accessed 29/04/2020. 14. AMH Online. Intranasal decongestants. Australian Medicines Handbook. Adelaide: Australian Medicines Handbook Pty Ltd, January 2020 edn. Accessed 29/04/2020.