pseudohaemoptysis

Pseudohaemoptysis

• is the appearance of blood in the sputum or when coughing, but the blood originates from a source other than the lungs or lower respiratory tract, such as the upper respiratory tract (nose, throat) or the gastrointestinal tract
  • there is blood in the expectorant, but the source is not the lower respiratory system, differentiating it from true hemoptysis
    
• causes of pseudohaemoptysis include:
  • haematemesis aspirated into the lungs
  • bleeding from the upper airway or the mouth for example epistaxis
    • blood can trickle down the back of the throat and stimulate a cough reflex and be expectorated, mimicking hemoptysis
  • Serratia marcescens lower respiratory tract infection
    • Serratia marcescens bacterium can produce a red pigment called prodigiosin, which can stain sputum red, creating the appearance of blood without actual blood cells being present

The pH of blood in true hemoptysis is alkaline, whereas, in case of pseudohemoptysis, the source of bleed is usually upper aerodigestive tract (1)

• presence of food particles, nausea, and acidic pH of the blood indicates gastric source of the bleed

The blood in haemoptysis is bright red in color and may be mixed with sputum and frothy (2)

• the blood in haemetemesis is dark red or brown and may be mixed with food particles

Associated pulmonary symptoms are important in the evaluation of haemoptysis (3)

• such as chronic cough with sputum production, change in cough, shortness of breath on exertion, chest pain (especially of a pleuritic nature), and wheezing

Reference:

1. Ranjan M, Karade S, Sen S, Srinivas V. Pseudohemoptysis in an elderly due to Serratia marcescens pneumonitis. Med J Armed Forces India. 2018 Oct;74(4):383-385.
2. Gaude GS. Hemoptysis in children. Indian Pediatr. 2010 Mar;47(3):245-54.
3. Corey R. Hemoptysis. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd ed. Boston: Butterworths; 1990. Chapter 39.