Actinomycosis (A42)
ICD-10 code A42 and its subcodes identify different forms of actinomycosis, a rare bacterial infection caused primarily by Actinomyces species. These codes cover infections in various body parts including the lungs, abdomen, face and neck, central nervous system, and cases of sepsis related to this condition.
These codes help healthcare professionals precisely classify actinomycosis cases by location and severity. For example, A42.0 refers to pulmonary actinomycosis, also known as actinomycotic pneumonia or pneumonia caused by anaerobic bacteria. A42.1 is used for abdominal infections like actinomycotic colitis or hepatic actinomycosis. The cervicofacial form, including mandibular or submandibular infections, falls under A42.2. More serious systemic involvement such as actinomycotic sepsis or meningitis is coded as A42.7 and A42.81, respectively. The unspecified code A42.9 applies when the infection site is not clearly documented. Knowing these distinctions aids in accurate diagnosis, treatment planning, and billing for infections linked to Actinomyces bacteria.
Certain infectious and parasitic diseases (A00–B99)
Other bacterial diseases (A30-A49)
A42 Actinomycosis
- A42.0 Pulmonary actinomycosis
- A42.1 Abdominal actinomycosis
- A42.2 Cervicofacial actinomycosis
- A42.7 Actinomycotic sepsis
A42.8 Other forms of actinomycosis
- A42.81 Actinomycotic meningitis
- A42.82 Actinomycotic encephalitis
- A42.89 Other forms of actinomycosis
- A42.9 Actinomycosis, unspecified
Actinomycosis (A42)
Instructional Notations
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- actinomycetoma B47.1
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Actinomyces
A genus of gram-positive, rod-shaped bacteria whose organisms are nonmotile. Filaments that may be present in certain species are either straight or wavy and may have swollen or clubbed heads.
Actinomycosis
Infections with bacteria of the genus ACTINOMYCES.
Actinomycosis, Cervicofacial
A form of ACTINOMYCOSIS characterized by slow-growing inflammatory lesions of the lymph nodes that drain the mouth (lumpy jaw), reddening of the overlying skin, and intraperitoneal abscesses.
Typhlitis
Necrotizing inflammation of the CECUM (typhlon in Greek), sometimes spreading to the APPENDIX and/or the ILEUM. Symptoms include ABDOMINAL PAIN and DIARRHEA. Its pathogenesis is multifactorial. Typhlitis is often associated with NEUTROPENIA and chemotherapy in immunocompromised individuals (IMMUNOCOMPROMISED HOST).
