clinical features

Last reviewed 01/2018

The disease has a relatively long incubation period of 1-2 weeks. The clinical picture is extremely variable and dependent upon the mode of onset.

Features of a gradual onset include malaise, increasing fever, and muscular pains. Initially, the cough is dry but a mucoid and bloody sputum may occur as the disease progresses. Hepatomegaly and splenomegaly are common and are reported in 10 to 70% of cases. A faint macular rash resembling the spots of typhoid fever may be seen on the abdomen.

Features of a rapid onset include shaking chills, extreme fever and photophobia. There is often a generalised myalgia with spasm and stiffness of the back and neck which may be confused with meningitis.

A common feature is headache - diffuse, excruciating and often the major complaint. Chest pain, pleurisy with effusion, and friction rub occur rarely, and dyspnoea is marked only in severe psittacosis. Generally, the physical signs of pneumonia usually less prominent than symptoms and radiologic features would suggest.