Giant cell arteritis presenting as facial or jaw pain is the most important vascular emergency in this differential — jaw claudication (pain on chewing that resolves with rest) is the most specific symptom of GCA, present in approximately 40-50% of cases, caused by ischaemia of the masseter and temporalis muscles from external carotid artery vasculitis. The medicolegal principle: a GP who attributes jaw pain in an elderly patient to 'dental' or 'TMJ' causes without checking ESR and CRP, and the patient subsequently develops GCA-related anterior ischaemic optic neuropathy with permanent blindness, faces a significant medicolegal claim. Prednisolone 60 mg OD must be started immediately on clinical suspicion — before biopsy results are available. Carotid artery dissection can present with ipsilateral facial pain (from pressure on sensory nerves around the internal carotid artery) plus Horner syndrome — this triad (facial pain + ipsilateral Horner + neck pain) is diagnostic until proved otherwise and is a 999 emergency.

Trigeminal neuralgia is one of the most severe pain conditions in clinical medicine — patients describe it as electric shock, lightning bolt, or hot poker applied to the face, lasting only seconds but occurring up to hundreds of times per day. The International Headache Society classification distinguishes classical TN (caused by neurovascular compression of the trigeminal nerve root — typically by the superior cerebellar artery), secondary TN (caused by MS, tumour, or AVM), and idiopathic TN (no cause found on MRI). In primary care, the key diagnostic features are: the paroxysmal quality (seconds, strictly not constant), the trigger phenomenon (light touch — toothbrushing, eating, cold air), the strict unilateral distribution, and the absence of objective sensory deficit between attacks. Any patient with features suggesting TN and objective sensory loss (numbness between attacks) must have MRI brain to exclude secondary causes — this is mandatory. MRI is also recommended in all new TN diagnoses to exclude secondary causes and identify neurovascular compression for surgical planning.

The dental percussion test is one of the most clinically useful bedside investigations for facial pain in the orofacial region — gentle tapping on the crown of each upper or lower tooth with a metal object (pen top, dental mirror handle) identifies the specific tooth with periapical infection or pulpitis when the patient has jaw pain that cannot be clearly localised. The test is positive when the percussed tooth is significantly more painful than adjacent teeth. Combined with the cold test (ethyl chloride spray or ice applied briefly to the tooth — prolonged lingering pain beyond 30 seconds indicates irreversible pulpitis; no response indicates pulp necrosis suggesting periapical pathology), these two examinations identify dental causes in the majority of orofacial pain presentations. GPs should be confident performing these tests — they allow appropriate triage to emergency dental services and guide antibiotic prescribing when emergency dental access is unavailable. Document which tooth is affected and the clinical findings to facilitate handover to the dentist.

The cluster headache oxygen treatment is frequently not prescribed or available in primary care — subcutaneous sumatriptan 6 mg is the fastest-acting acute treatment (onset 5-15 minutes) but high-flow 100% oxygen (12-15 L/min via non-rebreathing face mask for 15-20 minutes) is similarly effective for approximately 70% of cluster headache attacks and has no systemic side effects. The NICE headache guideline (NG150) recommends that GPs prescribe both sumatriptan SC and an oxygen cylinder with a non-rebreathing mask for patients with cluster headache. In practice, oxygen prescribing for cluster headache is frequently not done in primary care — the GP needs to write an oxygen prescription (BOC Home Oxygen Service in England, via form Home Oxygen Order Form) specifying: cluster headache, 100% O₂ at 12 L/min, non-rebreathing mask. This should be done at the time of diagnosis to allow the patient to treat attacks at home, avoiding repeated A&E attendances.

Nasopharyngeal carcinoma is a rare but important 2WW diagnosis that can present primarily as facial pain or numbness — it arises from the nasopharyngeal epithelium with strong EBV association and highest prevalence in Chinese, Southeast Asian, and North African populations. The triad: unilateral facial numbness (V2 distribution — maxillary nerve compression from skull base involvement), bloody nasal discharge or unilateral nasal obstruction, and unilateral upper cervical lymphadenopathy (cervical metastasis present in over 70% at diagnosis). Despite advanced stage at presentation being common, NPC is highly radiosensitive and chemosensitive — 5-year survival for stage I is over 90%. GPs should maintain a low threshold for 2WW referral in any patient of Chinese or Southeast Asian heritage with unexplained unilateral nasal symptoms, facial numbness, or cervical lymphadenopathy. NICE NG12 includes NPC in the suspected cancer pathways for head and neck cancer.

The carbamazepine response in trigeminal neuralgia is quasi-diagnostic and can be used therapeutically before MRI results are available — if a patient with suspected TN achieves complete or near-complete pain relief within 24-48 hours of starting carbamazepine 100 mg BD, this response strongly supports the TN diagnosis. No other facial pain condition responds in this specific, dramatic way. The mechanism: carbamazepine blocks voltage-gated sodium channels in the trigeminal nerve, suppressing the ectopic firing that generates the paroxysmal pain. Key prescribing pitfalls: (1) always start at 100 mg BD and titrate slowly — starting too high causes nausea, dizziness, and diplopia that leads to unnecessary drug discontinuation; (2) monitor serum sodium at 6 weeks (hyponatraemia is common, particularly in elderly women); (3) HLA-B*1502 testing is mandatory before prescribing in Han Chinese, Thai, or Filipino patients — carriers have up to 10% risk of Stevens-Johnson syndrome, which is fatal in approximately 5% of cases.

The combination analgesic approach for acute dental pain is significantly more effective than either drug alone — a meta-analysis (Moore et al., 2015, Cochrane Oral Health Group) demonstrated that ibuprofen 400 mg + paracetamol 1000 mg together provided an NNT of approximately 1.6 for 50% pain relief in dental pain, compared to NNT 2.5 for ibuprofen alone and NNT 3.5 for paracetamol alone. This combination should be the first-line recommendation for dental pain awaiting treatment — prescribed as a regular (not PRN) schedule: paracetamol 1g every 6 hours + ibuprofen 400 mg every 8 hours (with food). The regular scheduling maintains plasma levels and prevents pain peaks, which is far more effective than taking analgesics after pain has re-emerged. This approach frequently allows adequate pain control for 3-7 days while awaiting dental treatment and avoids unnecessary opioid prescribing for dental pain.

The cluster headache home oxygen prescription is one of the most impactful but most frequently omitted interventions in UK primary care — patients with cluster headache typically attend A&E repeatedly during each cluster period because they have no effective treatment at home. High-flow oxygen (100% O₂ at 12-15 L/min via non-rebreathing face mask for 15-20 minutes) terminates approximately 70% of cluster headache attacks and has no systemic side effects or drug interactions. NICE NG150 specifically recommends that GPs prescribe oxygen for cluster headache. The oxygen is prescribed via the NHS Home Oxygen Service (Home Oxygen Order Form, available on NHS England website) specifying: indication (cluster headache), flow rate (12-15 L/min), interface (non-rebreathing face mask), and that it is for acute use only (not continuous). Combined with subcutaneous sumatriptan 6 mg (the fastest-acting triptan, terminating attacks in 5-15 minutes), these two treatments should eliminate the need for most cluster headache A&E attendances.

The safety-netting message for all patients over 50 presenting with facial pain must include explicit GCA warning signs — even if GCA has been clinically excluded at the consultation, the safety-netting statement is essential: 'Because of your age, I want you to know that if you develop pain in your jaw on chewing that stops with rest, new temporal headache, scalp tenderness, or any sudden visual change in one eye, you should go to A&E immediately — do not wait for a GP appointment.' Document this safety-netting in the clinical record. Visual loss from GCA is permanent and can occur within hours — the safety-netting conversation and documentation takes 60 seconds and can preserve a patient's vision for decades. The ESR and CRP result should also be documented at every consultation for facial pain in a patient over 50, with a note on whether GCA was considered and the reasoning for exclusion.