Clinical clangers: ‘My ear infection is back again, can I get something to clear it up properly?’

In the latest in our series highlighting clinical scenarios that can commonly be mishandled in primary care, Dr Keith Hopcroft advises on a potential misdiagnosis of earache symptoms

The scenario
You see a 35-year-old woman in surgery, who grumpily announces: ‘I’m back here with my ear infection, doctor.’ The records confirm that she has attended on a number of occasions in the past year or two with earache, received diagnoses oscillating between otitis media and externa, and been prescribed various eardrops and antibiotics. Examination reveals a completely normal ear canal and tympanic membrane, but she has a tender and clicky temporomandibular joint (TMJ). You start to explain these findings to her and can’t help noticing her clenching her jaw and grinding her teeth.

The reality
Ear pain, or other ear symptoms, aren’t invariably infective – there are other causes, TMJ dysfunction being a common (and commonly overlooked) one. 

The issue
TMJ dysfunction is extraordinarily common. Up to 70% of the population have some features, although only a minority of these – about a quarter – have symptoms, and only 5% actually attend.¹ The usual presenting symptom is pain, which can be localised to the TMJ or can radiate to scalp, neck or shoulder. Other common symptoms including a clicking or crunching joint and restricted jaw movement.

What is much less well recognised is that TMJ dysfunction can cause a variety of other symptoms, including subjectively impaired hearing, tinnitus and vertigo.^2,3 The mechanisms underlying these symptoms are unclear. Understandably, this can mislead the unwary into suspecting some other diagnosis. 

Add this to the fact that assessment of an ear canal or ear drum is subjective, can be technically difficult and can be prone to the creative detection of borderline inflammation (especially on Friday evenings or in demanding patients), and it is not surprising that TMJ dysfunction can be confused with other diagnoses.

The evidence
There is no clear evidence quantifying how often TMJ symptoms are misdiagnosed as some other otological pathology, but certainly, in my experience, it seems to happen quite often (unless I am erroneously overdiagnosing TMJ dysfunction). Various authors of research and review papers state the same, claiming that it is frequently misdiagnosed or overlooked, although none offers any solid evidence for this.

Avoiding a clanger
Simply being alert to how common TMJ pain is, especially as a cause of earache when the ear canal and tympanic membrane look normal, should help aid correct diagnosis. It’s also important not to be misled by less well recognised symptoms such as impaired hearing, vertigo or tinnitus – if the clinical picture fits for TMJ dysfunction, then that could be the cause of these symptoms, too. 

Incorrect diagnosis tends to self-perpetuate, with patients, and often doctors, colluding with and reinforcing previous diagnoses of otitis media or externa.

Caveats
Given that asymptomatic cases are so common, it is quite possible that finding TMJ dysfunction on examination could be a red herring in a case of earache. So, while it is undoubtedly overlooked at times, other possible causes do need to be considered unless the diagnosis is clear – these include dental issues and temporal arteritis.

Dr Keith Hopcroft is Pulse’s medical advisor and a GP in Basildon, Essex

References

1. Dimitroulis G. Temporomandibular disorders: a clinical update. BMJ 1998;317:190
2. Henderson D, Cooper J, Bryan G et al. Otologic complaints in temporomandibular joint syndrome. Arch Otolaryngol Head Neck Surg 1992;118:1208–1213
3. Chole R, Parker W. Tinnitus and vertigo in patients with temporomandibular disorder. Arch Otolaryngol Head Neck Surg 1992;118:817-821