Allergy goes on
At the end of summer those with hay fever can sigh with relief, however our thoughts then turn to what the coming seasons might hold in the way of health issues. Allergens such as house dust mites, weed pollens and moulds, as well as indoor pets, are still likely to provoke sensitised allergic rhinitis. A gentle douching of the nose after close contact with these allergens can still help to reduce symptoms.
The common cold
Other forms of rhinitis become very frequent towards the end of the year, with infectious rhinitis being the most predominant. In September when children return to school, they often carry with them one of the hundreds of viruses which are the cause of colds. These include rhinoviruses, respiratory syncytial viruses, corona viruses, adenoviruses, coxsackie viruses, and echo-, ortho- and para- myxo and enteroviruses. Since there is no cross-protection between the different viruses, other children with whom they come into contact often catch the cold and suffer symptoms for 5-10 days. Interestingly these symptoms, which arise some 48 hours after infection starts, are actually mainly due to the immune reaction to the virus, rather than to the virus itself.
Most children suffer around 8-10 viral colds each year. Those children with allergies such as asthma and allergic rhinitis suffer more colds with worse symptoms and for longer, as there appears to be synergy between allergic and infective inflammation. Indeed the most common cause of asthma exacerbations are rhinovirus infections with peaks at the start of each school term, particularly the September one. It is not only children who are affected: classically the school child returns home and transmits the virus to others in the family, sometimes exacerbating their asthma too. Adults tend to have fewer colds, some 2 to 3 per year; this figure is higher in women and others in close contact with children.
The rhinovirus causes not only rhinitis but rhinosinusitis, since the sinuses are also inflamed. This can be seen on CT scans and has been shown to take some 6 weeks to resolve. This is likely to be the reason why sinus CT scans are abnormal in one third of adults and almost half of the paediatric population, and it is why it is vital that the CT is not used as a sole arbiter in ENT diagnosis.
Additionally, in babies and smaller children the middle ear is frequently affected with acute otitis media, followed in some by an effusion (secretory otitis media, or glue ear) which, like the sinuses, takes several weeks to resolve.
A common case study for colds
A typical story is that of the Jones family, whose older child Tom has just gone to school aged 4 ½ years, having previously been at nursery. He catches a cold in the second week of term, but is not too bothered by it. His nose is blocked and Stérimar brings some relief. However his baby brother Dylan, aged 16 months, gets it too after a few days and poor Mrs Jones has to cope with him screaming with pain and rubbing his ears all one night before she hurries to their GP next morning.
The GP examines Dylan and notes very red swollen ear drums and a blocked nose with thick yellow discharge. He diagnoses a viral infection and explains that the thick yellow discharge is not a sign of bacterial infection, but represents all the white blood cells which are responding to the virus. He recommends simple treatment with non-aspirin painkillers, nasal decongestant and baby saline nasal douching.
Dylan recovers over a few days, probably helped by the fact that he is still breastfed each night. Mrs Jones though has by now caught the cold too and her pre-existing asthma, and becomes very much worse so that she needs a course of oral corticosteroids as well as an increase of her asthma preventer before she is well again. Her father, previously a heavy smoker, has COPD which is worsened when he finally gets the same cold followed by a bacterial chest infection which necessitates antibiotics.
The causes of colds
Is any of this preventable? There is some evidence that people who exercise regularly are less likely to catch colds. This may relate to Vitamin D levels which are raised by sun exposure, and which are important for respiratory immunity. Vitamin D supplementation of those with low levels, found commonly in the Northern Hemisphere, might reduce colds. Psychological stress and allergic diseases also increase the likelihood of catching colds. Rhinoviruses, which are responsible for about half of all colds, invade the body via the posterior part of the nose and latch on to receptors on epithelial cells called ICAM_1, which are up-regulated in allergy.
Once infected, the cell produces a new generation of viruses within 8 hours. The viruses can reach the nose either directly or via the hands; when an infected person sneezes, droplets of mucus fly out into their hands or into the air. If someone else inhales these droplets or gets them on their hands by shaking hands, touching infected objects such as stair- rails, doorknobs, etc., they can then transfer the virus to their nose directly or via their eyes (as we touch our faces hundreds of times each day).
Simple advice such as catching sneezes in a tissue, binning it and killing it, as well as frequent hand washing, can reduce cross-infection; wearing gloves on crowded public transport and douching the nose with saline after travelling might also help. Avoiding those with colds if you have COPD, asthma or are immune-compromised is sensible, but cannot always be achieved since patients are contagious even before they are symptomatic.
There remains no reliable treatment for the common cold, despite years of research. Antibiotics are ineffective against viruses and should not be used. Vitamin C has not been proved to be effective, while Echinacea and zinc may have modest effects; the latter as lozenges may decrease symptoms and the cold’s duration. Zinc in spray form used as soon as the initial slightly sore nasopharynx becomes apparent, and continued to be used regularly for a few days, has demonstrated a reduction in cold symptoms, but some users experienced loss of their sense of smell. However, this could have been caused by the cold itself. Honey (10g) at night can reduce coughing.
Decongestants and hypertonic saline douching can also help the engorged nose.
This viral infection is not the same as the common cold. It can be very severe, but can be prevented and there is available treatment.
Seasonal winter flu epidemics occur every year caused by influenza A or B, occasionally C. Flu affects nose, throat and lungs and can be mild, or severe enough to kill. Transmission is by droplets.
This contagious respiratory illness is a preventable disease because an effective vaccine exists. A vaccine is produced each year to cover the strains of virus expected to be circulating.
Symptoms can include fever, sore throat, cough, runny or blocked nose, muscle aches, fatigue, headache, occasionally vomiting and diarrhoea. Sufferers are contagious for a day prior to developing symptoms and for about a week afterwards.
Complications include pneumonia, ear and sinus infections, meningitis, encephalitis, dehydration, cardiac failure and worsening of pre- existing medical conditions such as asthma. The very old and the very young, pregnant women, those with conditions such as diabetes , asthma , heart disease, immune suppression and those in nursing homes are most at risk, and should be vaccinated early in the season. Health care workers also need vaccination. In fact the 2012 USA recommendation is for everyone over 6 months of age to receive a flu vaccine, except for those with contra-indications such as a previous severe reaction to it. The UK strategic objective is to vaccinate at least 75% of those at greatest risk before the virus begins to circulate and to offer anti-viral medicines to those in at-risk groups.
If flu is suspected, the patient should rest at home, avoid contact with people, drink plenty of fluids and consider using paracetamol and/or ibuprofen to lower their temperature and relieve aches and pains. Anti-viral medicines which inhibit viral replication can be prescribed for at risk patients by their GPs.
- There are hundreds of cold viruses
- Babies suffer 8-10 colds a year because their immune system is less well developed and they're more vulnerable to infection. Adults have fewer colds, some 2 to 3 a year
- Antibiotics are ineffective against viruses and should not be used
- Women are more likely to catch cold, probably because they more often come in contact with children
- People are more likely to catch a cold during the winter season
- Some research suggest that cold weather could cause constriction of veins in the nasal linings, preventing the immune system from tackling viruses
Medical information written by Glenis K. Scadding, MD FRCP, Honorary Conultant Allergist & Rhinologist, RNTNE Hospital, London