From the Guidelines
Treatment guidelines for a positive PPD test vary by age and risk factors, with the preferred treatment for most patients being isoniazid (INH) 300mg daily for 9 months, which provides optimal protection with 90% efficacy 1. For individuals with a positive PPD test indicating latent tuberculosis infection (LTBI), the following guidelines apply:
- Children under 18 should receive INH 10-15mg/kg daily (maximum 300mg) for 9 months.
- Alternative regimens include INH 900mg twice weekly for 9 months (directly observed), rifampin 10mg/kg daily (maximum 600mg) for 4 months, or the newer 3-month regimen of weekly INH 900mg plus rifapentine 900mg (maximum dose) for those 12 years and older.
- For children aged 2-11, rifapentine dosing is based on weight (300-900mg) 1. Key considerations for treatment decisions include:
- Patient's age
- Risk of progression to active TB
- Medication side effects
- Potential drug interactions High-priority groups for treatment include:
- Individuals with HIV
- Recent conversion (within 2 years)
- Chest X-ray findings consistent with prior TB
- Young children Before starting treatment, active TB must be ruled out through symptom assessment, chest X-ray, and sometimes sputum testing, as treating active TB with a single drug can lead to resistance 1.
From the FDA Drug Label
Candidates for preventive therapy who have HIV infection should have a minimum of 12 months of therapy. All infants and children younger than 4 years of age with a > 10 mm skin test are included in this category. Recent converters, as indicated by a tuberculin skin test (≥ 10 mm increase within a 2-year period for those < 35 years old; ≥ 15 mm increase for those ≥ 35 years of age). Persons under the age of 35 with a tuberculin skin test reaction of 10 mm or more are also appropriate candidates for preventive therapy if they are a member of any of the following high-incidence groups Children who are less than 4 years old are candidates for isoniazid preventive therapy if they have > 10 mm induration from a PPD Mantoux tuberculin skin test persons under the age of 35 who ... have a tuberculin skin test reaction of 15 mm or more, are appropriate candidates for preventive therapy.
The treatment guidelines for a positive Purified Protein Derivative (PPD) test by age are as follows:
- Infants and children younger than 4 years: > 10 mm skin test
- Persons under 35 years:
- ≥ 10 mm increase within a 2-year period for recent converters
- ≥ 10 mm for those in high-incidence groups
- ≥ 15 mm for those not in high-incidence groups
- Persons 35 years and older:
- ≥ 10 mm increase within a 2-year period for recent converters
- ≥ 15 mm increase for recent converters
- Additional risk factors should be considered when deciding on preventive therapy 2
From the Research
Treatment Guidelines for Positive PPD by Age
The treatment guidelines for a positive Purified Protein Derivative (PPD) test vary by age and other factors.
- For children under 5 years old, the treatment regimen typically consists of 6 months of daily isoniazid therapy 3.
- For children between 5 and 14 years old, the treatment regimen may include 6 months of daily isoniazid therapy or 3 months of daily isoniazid and rifampicin therapy 3.
- For adults, the treatment regimen typically consists of 6 months of daily isoniazid therapy, but may also include 3 months of daily isoniazid and rifampicin therapy in certain cases 3, 4.
- Patients with a positive PPD who are prescribed biologic therapy, such as etanercept, should be screened for latent tuberculosis infection (LTBI) and treated accordingly to reduce the risk of TB reactivation 4, 5.
Special Considerations
- Patients with certain medical conditions, such as HIV, may require special consideration when treating a positive PPD result 3, 5.
- The use of biologic therapy, such as anti-TNF agents, may increase the risk of TB reactivation in patients with LTBI, and therefore requires careful screening and management 4, 5.
- The treatment regimen for LTBI may vary depending on the individual patient's risk factors and medical history 3, 5.