From the Guidelines
The diagnosis of Mycobacterium-induced interface dermatitis should be based on a combination of clinical, pathological, and radiographic findings, as well as the results of microscopic examination of acid-fast bacilli (AFB)-stained specimens and cultures for mycobacteria, as recommended by the American Thoracic Society 1. The diagnosis of Mycobacterium-induced interface dermatitis can be challenging, and a definitive diagnosis requires a comprehensive approach. The following steps can be taken to diagnose Mycobacterium-induced interface dermatitis:
- Clinical evaluation: A thorough clinical evaluation, including a physical examination and medical history, is essential to identify signs and symptoms of Mycobacterium-induced interface dermatitis.
- Laboratory tests: Laboratory tests, such as AFB-stained specimens and cultures for mycobacteria, can help confirm the diagnosis.
- Radiographic findings: Radiographic findings, such as chest radiographs, can also be useful in diagnosing Mycobacterium-induced interface dermatitis.
- Purified protein derivative (PPD)-tuberculin skin test: A PPD-tuberculin skin test can be performed to support the diagnosis of culture-negative pulmonary tuberculosis or latent tuberculosis infection in patients with stable abnormal chest radiographs consistent with inactive tuberculosis 1. It's essential to note that a negative PPD test does not exclude the diagnosis of active tuberculosis, but a positive skin test supports the diagnosis of culture-negative pulmonary tuberculosis or latent tuberculosis infection 1. The treatment of Mycobacterium-induced interface dermatitis typically involves a combination of antibiotics, such as rifampicin, ethambutol, and clarithromycin, for several months, as well as topical corticosteroids to manage inflammation and symptoms 1. The treatment should be continued for at least 6 months, and potentially up to 12 months, depending on the severity and response to treatment, to prevent antibiotic resistance and ensure complete eradication of the infection 1.
From the Research
Diagnosis of Mycobacterium-induced Interface Dermatitis
There are no specific studies provided that directly address the diagnosis of Mycobacterium-induced interface dermatitis. However, the following information can be gathered from the available studies:
- The diagnosis of nontuberculous mycobacterial (NTM) cutaneous infections can be challenging and requires a high index of clinical suspicion 2.
- Chronic cutaneous lesions at the sites of trauma or surgical procedures, especially those that fail to respond to standard antibiotic therapy, should prompt the consideration of mycobacterial disease 3.
- Deep tissue biopsy cultures are indispensable to determine the species and strain of mycobacterium, with important consequences for treatment 4.
- Some key considerations in the diagnosis of NTM infections include:
- Clinical presentation: NTM infections can present with a range of symptoms, including indolent nodules, sporotrichoid spread, acute suppurative folliculitis, and abscess formation 5.
- Exposure history: Patients with NTM infections often have a history of exposure to an aqueous environment 5.
- Laboratory tests: Cultures and drug susceptibility testing can help guide treatment decisions 6.
- Imaging studies: May be useful in evaluating the extent of disease and guiding biopsy procedures.