I wrote some time ago about how our little one was teething and the measures we’d taken to alleviate his discomfort. Well, this little chapter is still in full swing, with a mere two teeth erupted so far. But this isn’t a place to write long diary entries detailing my child’s progress; instead, I want to bring some science to light.
I’ve heard a number of physical signs regularly attributed to teething, such as rosy cheeks, diarrhoea, green faeces, fever, gnawing, irritability and drooling to name a few. It seems these beliefs are fairly common, as surveys of parents and health professionals have shown.
It gets interesting, however, when you look at some of the research done in this area. There seems to be some disagreement over which symptoms are actually caused by teeth eruption, and whilst it’s clear that individual babies will display different teething signs, it’s also apparent that some beliefs are not borne out by the evidence.
One of the difficulties is that the onset of teething (6-12 months) often occurs around the same time that babies become particularly susceptible to a variety of infections and upsets. This is mainly due to the decline in immunity imparted by maternal antibodies, as well as changes in behaviours that see infants actively interact with their environment.
There certainly seems a fair amount of evidence that many signs assumed to be caused by teething are actually caused by something else, such as meningitis, bacterial infection and herpes simplex virus infection. As the NHS Clinical Knowledge Summary bluntly puts it: “Teething does not cause children to become systemically unwell”.
Another problem is our familiar foe: limited experimental design. Studies in this area are rather limited in number, often rely on self-reporting rather than objective measurement, deal with correlations not causations, and many look back at clinical data rather than tracking babies as they develop. These complications may be exacerbated by the fact that many health professionals hold erroneous beliefs too, which influences the data collected.
So what do we know?
Symptoms often misattributed teething:
- Diarrhoea: This is one of the most common symptoms attributed to teething, but no solid data exist to suggest this is due to teething in the majority of cases. It has been tentatively suggested that slightly looser stools may occur during teething and this could lead to mild nappy rash.
- Fever: Teething may cause a small rise in body temperature, but a feverish temperature above 38°C is unlikely to be due to teething.
- Runny nose: The jury’s out on this one, but the reported associations are weak and this symptom is more likely to be a due to a wider problem.
- Wakefulness: While teething may cause some disruption of sleep, this is probably over-exaggerated by parents, and may be partly down to changing sleep patterns and the formation of attention-seeking habits. I was also told by a midwife that teeth move more during the night, causing greater wakefulness – I initially thought not, as it seems more reasonable that the distress is apparent when there isn’t anything to distract the infant. Any data on this latter point would be gratefully received!
- Green faeces: This is one I’ve heard a number of times, sometimes with an explanation of a change in the stomach acid balance. I can’t find anything in the literature (but please come forth and proffer!) but, on the face of it, it doesn’t seem to chime with idea that teeth eruption does not cause systemic upset.
Symptoms more likely to be caused by teething:
- Drooling: Excessive saliva can form and this may be seen by an infant dribbling more than usual. This isn’t conclusive, though, as salivary glands become active around 2–3 months of age and constant drooling can be expected then.
- Gnawing: Teething infants may gnaw on cold, hard objects or on their fingers to temporarily help with teething discomfort.
- Mild irritability: The pain associated with teething, which is mostly associated with an inflammatory response within the gums, might cause grizzliness, disturbed sleep, ear rubbing and a decreased appetite.
- Rosy cheeks: This is some support in the literature that flushed, red cheeks are associated with teething, although this is not clear-cut.
As I said earlier, different babies will experience different symptoms and it’s worth bearing in mind that no single symptom can definitively ‘diagnose’ teething.
Many of these beliefs appear to have some root in history as far back as Hippocrates in the 4th century, when teething was thought to be a deadly disease (“dentition difﬁcilis”, Latin for ‘difﬁcult teeth’). Teeth eruption, it was believed, caused a disturbance in the infant’s nervous system, leading to severe systemic upset. This was, again, most probably due to coincidental timing of onset of teeth eruption and an increased likelihood of serious infection, which in those days often led to infant death. Worse still, many of the treatments used for teething right up until the 19th century were actually toxic, such as opiates, lead, mercury salts, bromide and salt.
So while some studies have suggested that teeth eruption is associated with certain physical symptoms, none has really been able to establish causal relationships, and others have found no associations at all. It may be that a diagnosis of teething can relieve parents’ anxieties about an upset infant. Understanding true causal factors, however, is important to prevent misdiagnosis – attributing symptoms to teething could miss more serious conditions that require immediate medical attention.
P.S. I was hampered in my access to a lot of the research in this area, and so if I’ve missed anything then please let me know. A good argument to support Open Access publishing!