What clinical features should I look for to confirm a diagnosis of mumps in a patient presenting with parotitis?

To confirm a diagnosis of mumps in a patient presenting with parotitis, look for the following clinical features:

• Unilateral or bilateral parotid gland swelling: Typically painful and tender swelling of the parotid glands, often starting unilaterally and may progress to bilateral involvement within a few days ¹ (Hviid et al., 2008).
• Prodromal symptoms: Fever, malaise, headache, and myalgia usually precede the gland swelling by 1-2 days ¹ (Hviid et al., 2008).
• Trismus or difficulty opening the mouth: Due to inflammation and swelling of the parotid gland ¹ (Hviid et al., 2008).
• Other salivary gland involvement: Although less common, swelling of other salivary glands such as the submandibular glands may occur (Hviid et al., 2008).
• Absence of purulent discharge from Stensen’s duct: This helps differentiate mumps from bacterial parotitis ¹.
• Systemic features: Orchitis in post-pubertal males, oophoritis, pancreatitis, and meningitis can be associated but are not required for diagnosis (Hviid et al., 2008).

In summary, the hallmark clinical feature to confirm mumps is the characteristic painful parotid swelling accompanied by prodromal systemic symptoms, with exclusion of bacterial causes by absence of purulent discharge and other signs ¹ (Hviid et al., 2008).