Talcosis

Talcosis is the lung disease caused by inhaled or intravenously injected talc, hydrated magnesium silicate, usually contaminated with silica, tremolite or asbestos fibres. Three settings exist: occupational (talc miners, millers, and workers in rubber, paper, ceramics, paint and cosmetics), intravenous drug use (crushed oral tablets containing talc as filler injected into the venous circulation), and inhalation of talcum powder, rare but reported in infants.

Pathology depends on route. Occupationally inhaled talc causes a pneumoconiosis with nodular and interstitial fibrosis and foreign body giant cells containing birefringent needles and plates, and pleural plaques when fibres are present. Intravenous talc embolises to pulmonary arterioles, causing foreign body granulomas, perivascular fibrosis, pulmonary hypertension and panlobular emphysema in the lower zones, particularly with methylphenidate injection. Progression to fibrosis and cor pulmonale is common in heavy injection.

• Gradual exertional dyspnoea, dry cough, and fatigue.
• Occupational: crackles, mild restrictive impairment, pleural plaques on examination of chest film, clubbing in advanced disease.
• Intravenous: dyspnoea disproportionate to radiography, signs of pulmonary hypertension (loud P2, right ventricular heave, peripheral oedema), needle track marks, retinal talc crystals on fundoscopy (refractile yellow white particles in the macula).
• Acute talc inhalation in infants: respiratory distress, cyanosis, cough.
• Red flags: haemoptysis, syncope, rapid weight loss, signs of right heart failure.

• History: occupation, years of exposure, drug injection history.
• Chest radiograph: diffuse small nodules or reticulonodular opacities; upper zone conglomerate masses (ground glass, ill defined) in injectors; basal emphysema in methylphenidate injectors; pleural plaques in miners.
• High resolution CT: centrilobular and perilymphatic nodules, high attenuation conglomerate masses, panlobular lower zone emphysema, pleural plaques.
• Spirometry and DLCO: restrictive or mixed pattern with markedly reduced DLCO.
• Echocardiography: estimated systolic pulmonary artery pressure above 35 mmHg suggests hypertension; right heart catheterisation when mean pulmonary arterial pressure confirmation is needed (above 20 mmHg).
• Bronchoalveolar lavage or biopsy: birefringent needle shaped crystals under polarised light, foreign body granulomas.
• Exclude silicosis, sarcoidosis, tuberculosis, HIV-associated disease, and other pneumoconioses.

• Remove exposure completely: stop dust exposure or intravenous injection. Refer for opioid substitution therapy and addiction services where relevant: methadone 20 to 30 mg orally once daily initially titrated to 60 to 120 mg daily.
• No treatment reverses established fibrosis. Prednisolone 0.5 mg/kg orally once daily for 4 to 8 weeks then taper over 3 to 6 months may be tried when granulomatous inflammation or ground glass change is active; response is variable and often partial.
• Pulmonary hypertension: sildenafil 20 mg orally 3 times daily after specialist assessment; long term oxygen when resting SpO2 is 88 percent or below; diuretics for right ventricular failure (furosemide 40 mg orally once daily).
• Infections: treat promptly; tuberculosis screening annually in miners; HIV testing in injectors.
• Vaccination: annual influenza vaccine, pneumococcal conjugate vaccine once.
• Lung transplantation referral for end stage disease with sustained abstinence.
• Follow up: lung function and CT every 6 to 12 months; echocardiography annually.
• Prevention: ventilation, wet drilling and respirators in mines; harm reduction counselling and needle exchange for injectors.