Older patients with leukemia are susceptible to serious infections and complex pathogens due to hematopoietic and immune system damage. Common sites of infection include the lungs, soft tissues of the skin, gastrointestinal tract, and genitourinary system.
Respiratory infections
The incidence of respiratory infections is usually highest in older patients because of their own reduced lung function, reduced tissue elasticity, and less easily drained secretions in the trachea and bronchi, and even worse lung function in those with coexisting underlying lung disease.
Oral infections
Oral infections are mainly due to damage to the epithelial cells of the oral mucosa and weakened barrier protection caused by chemotherapy drugs, combined with post-chemotherapy bone marrow suppression, weakened body resistance, and dysbiosis of the normal oral flora.
In addition, because elderly patients mostly have oral diseases such as dental caries and residual teeth, and leukemia cells infiltrate the oral mucosa, which can lead to gingival hyperplasia and swelling, predisposing to oral ulcers and increasing the probability of nosocomial infection. Oral infections can also cause other organ and systemic infections, which directly affect the patient’s prognosis.
Bloodstream infections
Bloodstream infections are caused by pathogenic microorganisms invading the blood circulation, multiplying in the blood, inducing the release of various toxins and cytokines, causing systemic infections and inflammatory responses, and further causing alterations in blood pressure, coagulation and fibrinolytic system, and even systemic multi-organ dysfunction, which is one of the important causes of death from concurrent infections in patients with acute leukemia.
Advanced age, granulocyte deficiency, anemia, and hypoproteinemia are important risk factors for the development of bloodstream infections.
Perianal infections
Because of the specificity of the perianal region, most patients with perianal infections have difficulty talking about the discomfort in the perianal region, and thus the infection is not easily detected, leading to a missed diagnosis. Therefore, a detailed medical history should be taken to note the presence of hemorrhoids and anal fissures, which should be treated aggressively before chemotherapy.