Sialorrhoea

Sialorrhoea (drooling) is the unintentional loss of saliva from the mouth, caused not by excess saliva production in most cases but by impaired oromotor control and swallowing. It is physiological in infants up to 18 to 24 months and abnormal beyond age 4 years. It occurs in 10 to 80 percent of children with cerebral palsy, and in up to 70 percent of those with Parkinson disease, motor neuron disease, stroke, and learning disability.

True hypersecretion (ptyalism) follows drugs (clozapine, pilocarpine, cholinesterase inhibitors), organophosphate poisoning, mercury poisoning, gastro oesophageal reflux, oral inflammation, teething, and rabies. Normal saliva production is 0.5 to 1.5 L daily, with the parotid (25 percent, stimulated), submandibular (70 percent unstimulated) and sublingual glands (5 percent).

Consequences are perioral skin breakdown, angular cheilitis, dehydration, aspiration, social stigma, bad odour, speech difficulty, and impaired quality of life for caregivers. Impaired swallowing with aspiration pneumonia is the major medical hazard.

• Saliva spilling from the lips, wet clothing, perioral rash, and maceration.
• Poor lip seal, open mouth posture, tongue protrusion, reduced swallow frequency, drooling during head flexion.
• Neurological: hypomimia in Parkinson disease, bulbar signs and fasciculations in motor neuron disease, spasticity in cerebral palsy, hemiparesis in stroke.
• Cough with swallowing, wet voice, recurrent chest infections (aspiration).
• Drug induced: hypersalivation with nausea, sedation; cholinergic features in organophosphate poisoning.
• Red flags: acute onset with fever, dysphagia and neck stiffness (rabies, epiglottitis, retropharyngeal abscess), airway obstruction, and cholinergic syndrome.

• Clinical assessment; grade severity with the Drooling Severity and Frequency Scale (severity 1 dry to 5 profuse; frequency 1 never to 4 constantly) or drooling quotient (percentage of 5-second observations with drooling).
• Swallow assessment by speech and language therapist; videofluoroscopic swallow study or fibre optic endoscopic evaluation if aspiration is suspected.
• Drug review (clozapine, risperidone, neostigmine).
• Examine the mouth for caries, tonsillar hypertrophy, tongue lesions, and teething.
• Blood tests (renal function and electrolytes, glucose) and chest radiograph when aspiration is suspected; cholinesterase level if organophosphate exposure.
• Neurological workup for the cause.
• Exclude oral lesions, reflux, foreign body, infection (peritonsillar abscess), toxin ingestion, and rabies.

• Non-drug: positioning (upright head position), oromotor therapy and swallowing exercises, lip closure training, behaviour modification and cueing, oral hygiene, barrier cream (zinc oxide) for the chin, absorbent bibs, and orthodontic or oral appliances.
• Anticholinergics: glycopyrronium bromide oral solution 1 mg three times daily in adults (start 1 mg twice daily and increase by 1 mg every week, maximum 6 mg daily), or in children 3 years and over 20 micrograms/kg three times daily (maximum 100 micrograms/kg or 3 mg per dose), increasing every 5 to 7 days; give 1 hour before meals; adverse effects are dry mouth, constipation, urinary retention, flushing, irritability and thickened secretions.
• Hyoscine hydrobromide patch 1.5 mg applied behind the ear every 72 hours (children over 10 years); rotate sites; effects on vision and confusion.
• Atropine sulfate 1 percent eye drops, 1 to 2 drops sublingually 2 to 3 times daily (adult), or benztropine 0.5 to 1 mg orally twice daily; amitriptyline 10 to 25 mg at night for sedating benefit; avoid in glaucoma.
• Botulinum toxin A injection into the parotid and submandibular glands under ultrasound guidance: onabotulinumtoxinA 15 to 30 units per parotid and 10 to 20 units per submandibular gland (total 50 to 100 units in adults, 1 to 2 units/kg total in children); effect begins in 3 to 7 days and lasts 3 to 6 months; repeat every 4 to 6 months (adverse effects are dysphagia, chewing weakness, and dry mouth).
• Radiotherapy: single dose 8 Gy or 10 to 12 Gy over fractions to the salivary glands for refractory cases in adults.
• Surgery in refractory cases in children over 5 years: bilateral submandibular duct relocation with sublingual gland excision (success about 80 percent) or submandibular gland excision with parotid duct ligation; avoid when swallowing is poor.
• Organophosphate poisoning: atropine 2 mg intravenously every 5 to 10 minutes until secretions dry (the end point is clear chest on auscultation), pralidoxime 30 mg/kg intravenously over 30 minutes then 8 mg/kg per hour.
• Follow up: 2 to 4 weeks after starting drugs, then every 3 to 6 months; review swallowing and chest status.
• Counselling: caregivers should be taught positioning and skin care; surgery and toxin have a role in refractory cases.