The prognosis for Alternaria alternata infection varies depending on the severity of the infection and the overall health of the affected individual. In most cases of respiratory allergies caused by Alternaria alternata spores, the prognosis is good with proper treatment and avoidance of exposure to the spores. However, in individuals with severe allergies or underlying respiratory diseases, such as asthma, the prognosis may be more guarded. In plants, the prognosis for Alternaria alternata infection depends on the type of plant and the severity of the infection. Prompt diagnosis and treatment can help to limit the spread of the infection and reduce crop damage.