Lay Summary

What is the "common cold"?
The common cold is also known simply as a "cold" or in medical terms, as a viral "upper respiratory tract infection" (URTI). As the name implies, it is a common infection that is caused by a virus. Symptoms may include runny nose, cough with or without phlegm (mucous), congestion of the nose, throat and sinuses, sore throat, headache, swelling of the glands of the neck, fatigue, decreased apetite, poor sleep, irritability and sometimes fever. In otherwise healthy children, typical colds fully resolve within 1-2 weeks regardless of treatment.

How are colds treated conventionally?
Antibiotics are used to treat infections caused by bacteria and are therefore NOT effective against colds, which are always caused by viruses. Viral infections such as colds are not "curable" with over-the-counter medications, but some can help relieve symptoms. Acetaminophen or ibuprofen is used for discomfort from pain and fever. Saline nose drops can be used in small infants with nasal congestion that affects breathing and feeding. Cough medications, antihistamines and decongestants have not been shown to be effective in the treatment of colds in children, so they should not be used routinely. Children are encouraged to drink fluids to prevent dehydration, and may be more comfortable sleeping with the head of their bed raised in order to decrease nighttime congestion and cough. Eliminating cigarette smoke exposure is also helpful, since it can worsen cold symptoms and prolong recovery.

What is Complementary and Alternative Medicine (CAM)
Complementary and alternative medicine (CAM) is a group of diverse health care systems, practices and products that are not presently considered to be part of conventional medicine. (NCCAM. What is Complementary and Alternative Medicine? Health Information. 2002) Examples of CAM practices include massage therapy and acupuncture. Examples of CAM products (also known as natural health products) include Echinacea and St. John's wort.

What kinds of CAM are used to treat colds?
There are many CAM therapies used to treat colds. Many treatments have not been well studied in children, especially regarding effectiveness and safety. There are very few high-quality studies, and this can make it difficult to give good evidence-based advice. The information presented here is based on published research. In particular, randomized controlled trials (RCTs) of commonly used CAM and studies involving children were searched. For the common cold, the focus will be on 4 kinds of CAM:
- Natural health products (NHPs)
- Homeopathy
- Hydrotherapy
- Psychological interventions

Natural Health Products (NHPs)
NHPs are widely used for prevention and treatment of various conditions and to maintain health. Examples include herbals, homeopathic remedies, vitamins, minerals, probiotics, amino acids, and traditional medicines. Dosing and quality of products can vary significantly. NHPs commonly used to treat colds include herbal preparations, vitamins, minerals and probiotics.

Herbal remedies:
Chinese herbal medicine
A 1998 review of the literature on Chinese herbal medicines was unable to make conclusions about the safety or effectiveness of the preparations due to the poor quality of the studies.

Safety of Chinese herbal medicine
Some herbal preparations from China have been found to be contaminated with toxins (i.e. heavy metals such as mercury or arsenic) and/or adulterated with prescription medications such as steroids. Reports of allergic reactions, and side effects involving blood, liver, heart and lungs after drinking Chinese teas are well documented.

Andrographis paniculata
Andrographis paniculata (king of bitters) is a popular traditional Chinese herb that is often used to treat fever, sore throat, and respiratory and abdominal (gastrointestinal) infections. It has been used to treat and prevent colds.

In a 2004 Russian study involving children, Andrographis was better at improving cold symptoms compared to standard therapy (which included chamomile tea) or a preparation that contained Echinacea purpurea. Andrographis was also better than placebo in preventing colds in older children in a Chilean study published in 1997.

Safety of Andrographis paniculata
Although the studies in children reported no side effects, adult studies have reported stomach upset, loss of apetite, hives and vomiting.

Echinacea
Echinacea products vary widely in quality, depending on the species (usually Echinacea purpurea), the part of the plant used (root, herb or both), and the manufacturing methods. It is used to treat and prevent colds.

In children, there are few Echinacea studies, and the results are inconsistent. One large American study published in 2003 showed no difference in cold symptoms. Although there was some promising data about Echinacea for preventing colds, this needs to be confirmed before it can be recommended for this use. A 2004 Israeli study found that an herbal preparation containing Echinacea, propolis (natural bee resin) and vitamin C was better at preventing colds and fevers than placebo. However it was not possible to determine if the benefit was the result of the combination of the three products, or due to one or two of the ingredients.

Safety of Echinacea
Echinacea may cause mild side effects including stomach upset, skin rashes and increased urination. People with allergic tendencies, like asthma, eczema and hay fever, should not take Echinacea because they are at increased risk of allergic reactions that can be severe or potentially life-threatening (anaphylaxis). Echinacea may affect the immune system, so people with immune-related medical conditions (for example, autoimmune diseases), and those who are on medication that affect the immune system such as steroids, should also avoid Echinacea.

Vitamin C
Also known as ascorbic acid, the use of vitamin C for colds is controversial, and the results of many studies are inconsistent. A 2004 Cochrane systematic review found that, compared to placebo, vitamin C was not helpful in preventing colds, but may have an effect on decreasing the length and severity of colds.

Published research involving children in randomized controlled trials is scarce and tends to be older. An American study published in 1975 and repeated in 1976 by the same research group found that vitamin C was no better than placebo at preventing colds in Navajo children. A small study involving twins in 1977 also found no difference between vitamin C and placebo. There was also a possibility that younger patients, especially girls, may have had shorter and less severe colds. However the results of this study have not been confirmed in subsequent trials, so its conclusions remain unsubstantiated.

Safety of vitamin C
Normal doses are vitamin C are generally very safe in healthy individuals. Large doses can cause stomach upset and diarrhea. Because vitamin C is excreted through the kidney, people with kidney disease or kidney stones should not take it. Also, certain underlying medical conditions and medications can interact with vitamin C.

Zinc
Zinc deficiency is suspected to affect susceptibility to colds. Zinc supplements have been used to treat and prevent colds but the evidence is inconsistent. 4 large trials published between 1998 and 2003 in American or East Indian children showed conflicting results comparing zinc and placebo. 2 of the studies concluded that zinc decreased the length of colds by 1½ to 2 days but the other 2 studies found no difference. There was also a decrease in the number of colds using daily zinc for several months in 2 of the studies.

Safety of zinc
Side effects of zinc found in the above studies included bad taste and burning sensation on the tongue. Long-term effects are unknown, but zinc may potentially affect copper metabolism.

Probiotics
Probiotics are live microorganisms, usually bacteria, that are consumed as dietary supplements or added to foods such as yogurt. There are many different types (species or strains) of bacteria used, and they are thought to promote a healthy combination of bacteria in the gut (large intestines) that can help prevent or treat certain conditions and maintain general wellness.

A 2001 Finnish study found that daily probiotics were slightly better than placebo in preventing colds in children.

Safety of probiotics
While probiotics are likely safe in healthy people, consumers should be mindful that they are ingesting live organisms. There are case reports of severe and potentially life-threatening bacterial infections in children and adults with underlying medical problems including weakened immune systems.

Homeopathy
The principle that "like cures like" means that substances that cause symptoms at normal or high doses can cure them when given in small, highly diluted amounts.

2 Norwegian studies looked at homeopathy for prevention of colds in children. Both were published by the same authors in 2005. Homeopathic preparations of Calcarea carbonica, Pulsatilla or Sulphur were no better than placebo in preventing colds. However, individualized homeopathy was found to reduce cold symptoms in the second study.

Safety of homeopathy
Homeopathy is considered to be very safe since the preparations are very dilute, but it may be possible to trigger a reaction in an allergic person. Temporary worsening of symptoms, called "aggravation", can last a few hours and happens in 10-20% of patients.

Hydrotherapy
Hydrotherapy is the systematic stimulation of the body with warm and cold water.

A German pediatric study published in 2003 found that an individualized program designed by a hydrotherapist for each child did not prevent colds, or decrease the length of colds.

Safety of hydrotherapy
In the above study, 3 children reported feeling cold for prolonged periods of time after hydrotherapy.

Psychological interventions
A small Australian study published in 2001 looked at the effect of a stress management program or guided imagery for the treatment of colds in children. Both interventions were effective in shortening the length of colds, but made no difference to the frequency of colds.

Safety of mind-body techniques
There are no well-established tools to assess side effects of mind-body therapies, but studies suggest that 5-54% of people may experience some forms of anxiety, unpleasant sensations or thoughts, or muscle spasms. Factors associated with such experiences include fear of letting go or losing control, restlessness, and feelings of vulnerability. These side effects may cause some people to stop therapy. In other cases, the feelings are used to therapeutically to explore and cope with these fears. Adequate preparation and supervision of therapy may help minimize and prevent such effects.

Conclusions

There is research showing that CAM may help children with colds. However, many of the studies have significant limitations that make it difficult to offer advice with confidence based on their conclusions, whether positive or negative. These limitations include lack of safety information (especially long-term side effects), flaws in methodology, and small numbers of patients recruited. Evidence from a single trial of any specific CAM should encourage further study and confirmation of conclusions, and the use of such therapies should be supervised with caution by health care providers. Pediatric dosing is often unknown and the quality of some natural health products is unreliable, making safety a further concern. Adults respond to therapies in ways that children may not, therefore assumptions based on adult experience can be inaccurate or even harmful. Products given to prevent illness, rather than for treatment, are often given every day during susceptible periods. For colds, this means that children may be taking NHPs for many weeks or months during the winter season. Some therapies and products can be costly and add financial stress for families.

The following figure shows how the evidence for each CAM can be organized according to safety and effectiveness.

Green
Andrographis paniculata
Probiotics

Blue
Echinacea
Vitamin C
Zinc
Probiotics
Homeopathy
Hydrotherapy
Stress management techniques and guided imagery

Yellow
Chinese herbal medicine

The CAM therapies are organized into colour-coded categories for clarity. Conventional medications can also be categorized similarly. For instance, many over-the-counter medications would fall into the blue area, and many prescription medications would fall into the yellow area. Some pediatric health issues can be potentially serious, especially if the condition is chronic, or multiple therapies, NHPs and medications are used together. The decision to use CAM should be based on each child's health and include discussion with the child's physician.

All uncomplicated colds get better regardless of treatment. Each child is unique, and families must weigh the risks and benefits of all interventions as objectively as possible. This is especially important for therapies and products in which good evidence is limited or unknown. The information provided here is intended to promote discussion among parents and health care providers of children with colds, and is not meant to replace medical advice. More high quality studies are needed to guide recommendations about effectiveness and safety of CAM for treatment of colds, and to assist caregivers and families in making informed decisions about treatment options.

Funding: Partial funding support for this review was received from Passeport Santé.

Lay summaries: For more information in French, please see Passeport Santé.

Clinician summaries: Full scientific review article will be published in Pediatrics in Review.

Disclaimer: The information available on this website is intended to provide general information about complementary and alternative medicine (CAM). This website does not provide specific medical advice and the information provided should not be used as a substitute for seeking medical advice from a registered health practitioner. The opinions expressed on this website are not necessarily reflective of the opinion of the Stollery Children's Hospital, Capital Health Authority,Passeport Santé or Pediatrics in Review.