Blastomycosis (B40)
The ICD-10 code B40 and its subcodes classify different forms of blastomycosis, a fungal infection caused by the fungus Blastomyces dermatitidis. These codes are used to specify whether the infection affects the lungs, skin, or other organs, and whether it is acute, chronic, disseminated, or unspecified.
Healthcare professionals use codes like B40.0 for acute pulmonary blastomycosis, also called primary pulmonary blastomycosis, to document infections of the lungs with symptoms starting suddenly. For chronic lung infection, B40.1 is used. B40.3 covers cutaneous blastomycosis, which affects the skin, sometimes referred to as primary or disseminated cutaneous blastomycosis. The code B40.7 indicates disseminated blastomycosis, where the fungus spreads beyond the initial site. Other specialized forms, such as meningoencephalitis due to blastomycosis, are coded as B40.81. When the site of infection is unclear or involves other organs like the liver, heart, or eyes, B40.89 or B40.9 are applied. Using these ICD-10 codes for blastomycosis helps accurately record the specific fungal infection, guiding treatment and epidemiological tracking.
Certain infectious and parasitic diseases (A00–B99)
Mycoses (B35-B49)
B40 Blastomycosis
- B40.0 Acute pulmonary blastomycosis
- B40.1 Chronic pulmonary blastomycosis
- B40.2 Pulmonary blastomycosis, unspecified
- B40.3 Cutaneous blastomycosis
- B40.7 Disseminated blastomycosis
B40.8 Other forms of blastomycosis
- B40.81 Blastomycotic meningoencephalitis
- B40.89 Other forms of blastomycosis
- B40.9 Blastomycosis, unspecified
Blastomycosis (B40)
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.
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.
Blastomyces
A genus of onygenacetous mitosporic fungi whose perfect state is Ajellomyces (see ONYGENALES). The species Blastomyces dermatitidis (perfect state is Ajellomyces dermatitidis) causes blastomycosis.
Blastomycosis
A fungal infection by BLASTOMYCES that may appear in two forms: 1, a primary lesion characterized by the formation of a small cutaneous nodule and small nodules along the lymphatics that may heal within several months; and 2, chronic granulomatous lesions characterized by thick crusts, warty growths, and unusual vascularity and infection in the middle or upper lobes of the lung.
Lobomycosis
A chronic, fungal, subcutaneous infection endemic in rural regions in South America and Central America. The causal organism is Lacazia labol.
Paracoccidioidomycosis
A mycosis affecting the skin, mucous membranes, lymph nodes, and internal organs. It is caused most often by Paracoccidioides brasiliensis. It is also called paracoccidioidal granuloma.
