Lung Infections: Common Types and How to Treat Them

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Tuberculosis Triggered Giant, Crusty Wart To Sprout On Man's Hand

In a rare case, a man developed a crusty, giant yellow wart on his hand that was caused by tuberculosis (TB).

The 59-year-old, from China, had been suffering from the pain emanating from his wart for about a year before visiting a dermatology clinic.

There, doctors examined the wart, which covered the top of the patient's right hand and part of his right index finger. The clinicians described the growth as having an overlying "thick yellow-brown crusting." The man had no other symptoms besides the physical changes on his hand and the associated pain, according to a report of his case, published June 12 in The New England Journal of Medicine.

The doctors then took a tissue sample and analyzed it under the microscope, noticing that skin cells from the wart were growing thick and fast and large lumps of cells had formed within the middle layer, or dermis, of the skin.

Related: Woman's 'extra breast' under her armpit developed a wart-like tumor in unusual case

These lumps were tuberculoid granulomas, or clusters of immune cells that form to corral the bacterium that causes TB, Mycobacterium tuberculosis. These granulomas surround and attack the pathogen, triggering inflammation. Tuberculoid granulomas are a defining feature of TB and represent the body's attempt to thwart the infection.

Doctors analyzed DNA within the patient's wart sample and confirmed the presence of M. Tuberculosis. The tissue also tested positive on a major test for TB — the interferon-γ release assay — which looks for a protein produced by the immune system in response to M. Tuberculosis.

TB is one of the deadliest infectious diseases worldwide, having killed 1.3 million people worldwide in 2022. Most often, the disease affects the lungs and is spread between humans when an infected person coughs or sneezes M. Tuberculosis spores and another person inhales them.

In this case, the man didn't have TB in his lungs, as shown on a computed tomography (CT) scan of his chest. Instead, he had a rarer form of TB known as extrapulmonary TB, which affects other organs in the body and accounts for an estimated 20% of TB cases.

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Rarer still, the man turned out to be one of the 1.5% of patients with extrapulmonary TB whose infection specifically affects the skin. He was diagnosed with tuberculosis verrucosa cutis, which can happen when M. Tuberculosis enters the skin of someone who has been previously infected. The bacteria typically get in through an open wound or abrasion in the skin.

Patients with tuberculosis verrucosa cutis characteristically develop warty plaques at the site of infection, usually on their hands, knees or ankles. The condition is sometimes referred to as "prosector's wart," because of its historical connotations with people who worked in autopsy rooms.

The authors of the new case report didn't discuss how the man might have been infected. However, they noted that he was a veterinarian, which could be a possible risk factor. You're more likely to catch TB if exposure to mycobacteria comes as part of your job; frequent contact with livestock is a risk factor, for instance.

Just like TB that affects the lungs, tuberculosis verrucosa cutis is treated with antibiotics to clear the infection. The man was prescribed a six-month course of these drugs, and within two months, his wart had "abated," the doctors reported. Tuberculosis is highly curable, but treatment generally requires patients to take antibiotics for around six months.

This article is for informational purposes only and is not meant to offer medical advice.

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The Host And Pathogen Determinants Of Tuberculosis Spectrum Diseases

Tuberculosis (TB) prevails as a leading killer among infectious diseases of humans worldwide. Mycobacterium Tuberculosis (Mtb), the causative agent of TB, has co-existed with the human host for thousands of years. Tools currently available, including diagnostic modalities to identify patients, vaccines to prevent progression of Mtb infection into active disease, as well as anti-TB drugs are inadequate in fully alleviating the morbidity and mortality associated with TB. Therefore, improved intervention strategies are urgently needed for efficient containment.

Following exposure to Mtb-containing aerosol droplets, the bacteria reach alveoli and interact with the host innate cells, such as macrophages and epithelial cells. Engulfment of Mtb by alveolar macrophages elicits an early immune response that facilitates extravasation of immune cells from the blood to the site of infection, which ultimately leads to formation of the granulomas, a highly organized cellular structure. Although granulomas are thought to contain Mtb infection, the bacteria can resist killing by the host immune cells and persist intracellularly, by employing several virulence mechanisms. This includes resistance to host cell antimicrobial responses, escaping from the phagosome into the cytosol as well as metabolic adaptations to a dormant state. However, the local immunological niche that determines the fate of individual granulomas either towards bacterial containment or failure, is not fully understood. The intricate interactions of the host and pathogen derived factors ultimately determine the outcome of Mtb infection at the cellular and whole organismal level. However, due to the heterogeneity in the virulence of Mtb strains and clinical isolates, as well as the susceptibility/resistance of various host cells, our knowledge on the specific role of these cellular and molecular determinants of Mtb and host cells remains incomplete. Recent evidence also indicates the interplay amongst multiple cellular processes, such as metabolism and epigenetic remodeling in shaping the host immunity to Mtb. Although several in vitro cell culture systems as well as preclinical animal models have been utilised to unravel and understand the various host and bacterial determinants underpinning TB, the inter-connection between various host cellular processes and their impact on Mtb pathogenesis are not fully understood.

Despite recent advances, the intricate host-pathogen interactions and factors that contribute to differential clinical outcomes following Mtb infection remains largely unknown. Therefore, additional studies are needed from both the host and pathogen perspective to delineate the mechanisms underpinning TB pathology. The aim of this research topic is to stimulate discussion among investigators on various host and Mtb characteristics, that would contribute to better understanding of TB and help devise improved diagnosis and treatment options. The scope of this Research Topic is focused on the role of various components of host response, including innate, adaptive and trained immunity and immunometabolism, as well as Mtb virulence determinants and their adaptation features that contribute to TB pathogenesis. We invite original articles, mini reviews, reviews, perspectives and opinion articles that fits within the scope. Articles that address the following themes are particularly encouraged:

· Innate, adaptive and trained immune response in various model systems and humans with TB

· Immunometabolism and its impact on TB.

· Cellular signaling and networks of host cell-Mtb interactions.

· Genes and proteins of Mtb that contribute to TB pathogenesis.

· Target bacterial molecules for potential TB vaccine, drug and diagnostic purposes.

· Preclinical and clinical evaluation of potential vaccines and drugs for TB, including host directed therapy.

· Various pathophysiological states of TB in model systems and in humans.

· Co-morbidity of TB with other infectious and non-infectious diseases.

All of the editors for this Research Topic confirm that they have no conflicts of interest in relation to the publication of this collection.

Keywords: Tuberculosis, Mycobacterium, latency, reactivation, subclinical TB, TB, immune response, genetics, virulence, preclinical models, vaccines and drugs

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.