Laboratory diagnostics are usually not required for only short-term hoarseness.
Second-order laboratory parameters-depending on the results of the history, physical examination, and obligatory laboratory parameters-for differential diagnostic clarification.
- Throat swab/culture – for suspected diphtheria, streptococcal infections.
- Antistreptolysin titer (ASL) – detectable about 1-3 weeks after the onset of streptococcal infection; about 6 weeks after infection, the highest titers are measured; an elevated titer may remain measurable for several months after adequately treated infection and should be interpreted only as an indication of immunological challenge with group A streptococci.
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- Thyroid parameters – TSH
