[Impaired immunity: risk groups and consequences for general practice].

• Due to medication use, comorbidities and/or age, an increasing number of patients have an impaired immunity to infection.- Impaired immunity may lead to an increased risk of (opportunistic) infection, complications from infections, and difficulties in the diagnosis of infections.- Guided by clinical parameters, a general practitioner can classify an impaired immunity as 'clinically irrelevant', 'limitedly relevant' or 'potentially serious'.- Tocilizumab impairs the production of CRP, which makes it unreliable as an infection parameter.- In case of a suspected infection in patients with severe immunosuppression, it will often be necessary to consult a specialist as quickly as possible about further diagnostic procedures and the need for, type and administration route of antimicrobials.- In patients with an impaired immunity, adaptation of the antibiotic policy and prophylactic measures, such as vaccination, may be indicated.- Patients with (functional) asplenia should immediately start antibiotic treatment in case of fever, pending clinical evaluation by a physician.