Actinomyces causes actinomycosis.
Actinomycosis is a subacute and chronic bacterial infection characterized by contiguous spread and suppurative and gran-ulomatous inflammation. The condition is associated with the formation of multiple abscesses and development of sinus tracts discharging white to yellowish granules, known as sul-phur granules. Actinomycosis may manifest as (a) cervicofacial actinomycosis, (b) thoracic actinomycosis, and (c) actinomycosis of the abdomen and pelvis.
Cervicofacial actinomycosis: It is the most common mani-festation in humans comprising about two-thirds of reported cases. The infection occurs in the cervicofacial region, which typically occurs following oral surgery in patients with poor oral hygiene. Initially, the condition manifests as a swelling of the soft tissue of the perimandibular area and subsequently, during the course of the infection, the disease spreads directly into the adjacent tissues and leads to formation of fistulas. These fistulas or sinus tracts discharge purulent material containing yellow granules, known as sulfur granules. If left untreated, this condition may spread to the blood and eventu-ally to the brain and to the orbit.
Thoracic actinomycosis: This condition is responsible for15–20% of cases of actinomycosis. It is caused by aspiration of oropharyngeal secretions containing Actinomyces and occasion-ally during perforation of the esophagus. The condition also occurs by direct spread from an actinomycotic lesion of the nape of the neck or the abdomen, or through blood circulation from other distant sites. The condition commonly presents as a pulmonary infiltrate or mass involving the lung. The condi-tion, if left untreated, can spread outwardly through the pleura, pericardium, and chest wall, ultimately leading to the forma-tion of multiple sinuses that discharge sulfur granules.
Actinomycosis of the abdomen and pelvis: This conditionaccounts nearly 10–20% of reported cases. The ileocecal region is the most common site involved in the condition. The condi-tion typically presents as a slowly growing tumor. The infection subsequently spreads and involves abdominal organs includ-ing the abdominal wall, leading to the formation of draining sinuses. Actinomycosis of pelvis is commonly associated with prolonged (for many years) use of intrauterine contraceptive devices. The infection spreads directly from uterus to pelvis.
Actinomycosis is distributed worldwide. The condition is more common in rural areas and in farm workers. The condition is seen more commonly in individuals with poor dental hygiene and in the people with low socioeconomic conditions. Men are affected more commonly than women (male to female ratio is 4:3) with the exception of pelvic actinomycosis. Majority of the cases are reported in young and middle-aged patients.