Definition

Tuberculosis is a disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs but can also target other body parts, such as bones, the brain, intestines, and skin. Cutaneous verrucous tuberculosis is one of the many manifestations caused by this bacterial infection.

Causes

Cutaneous verrucous tuberculosis is caused by infection with Mycobacterium tuberculosis. The bacteria's primary host is humans, and transmission typically occurs through airborne droplets from coughing or sneezing by an infected person. However, direct exposure to infected skin can also lead to transmission.

This type of tuberculosis usually occurs when the bacteria enter the skin of a previously infected but currently healthy individual. Additionally, cutaneous verrucous tuberculosis can spread through occupational accidents in autopsy rooms.

Risk Factor

Cutaneous verrucous tuberculosis is more common in people with weakened immune systems due to illness or medications. Conditions like HIV/AIDS, diabetes, cancer, or other immune-related diseases can lower immunity, as can medications taken by organ transplant recipients or those with autoimmune disorders.

Occupations such as healthcare workers, pathologists (who study tissues under microscopes), and lab workers face increased risk due to potential contact with bacteria on infected skin. Children who play outside barefoot are also at higher risk due to the possibility of wounds on their feet becoming infected.

Symptoms

Cutaneous tuberculosis symptoms can be categorized into four main groups:

1. Exogenous Cutaneous Tuberculosis: Includes tuberculosis chancre and cutaneous verrucous tuberculosis.
2. Endogenous Cutaneous Tuberculosis: Infection spreads from a nearby organ (e.g., scrofuloderma, orificial tuberculosis, and some lupus vulgaris cases).
3. Tuberculids: Tuberculid papulonecrotic, scrofuloderma lichen.
4. Secondary Cutaneous Tuberculosis: Following Bacillus Calmette-Guérin (BCG) immunization.

Cutaneous verrucous tuberculosis presents as wart-like, purple, or reddish brown lesions. These skin lesions commonly appear on the knees, elbows, hands, feet, and buttocks. These sores can persist for years but may eventually heal without treatment.

In addition to these symptoms, individuals may experience classic tuberculosis symptoms, such as productive coughs, night sweats, weight loss, fever, hemoptysis (coughing up blood), chest pain, and fatigue.

Diagnosis

Diagnosis of cutaneous verrucous tuberculosis is based on the patient's history, symptoms, and physical examination. A history of immune suppression, such as from AIDS, uncontrolled diabetes, malignancy, or end-stage renal failure, can be an indicator. Repeated needle usage or immunosuppressive therapy may also be risk factors.

Tests may include the tuberculin skin test, which introduces Mycobacterium tuberculosis protein under the skin and observes the immune response. A positive result indicates a current or past infection; however, a negative result can occur if the immune system is too weak. Additionally, past BCG immunization can lead to a false positive.

A biopsy may also be performed to collect tissue samples from ulcers or lesions. This sample can be used for acid-fast bacilli (AFB) staining, histopathological examination, and bacterial culture. The AFB test examines bacteria in tissue under a microscope, while histopathology examines infected cells directly. The culture, considered the "gold standard" for detecting Mycobacterium tuberculosis, is incubated at a low temperature to observe bacterial growth. However, due to the low bacterial count in lesions, culture results may occasionally be falsely negative.

Doctors may also recommend chest X-rays and sputum analysis to check for pulmonary tuberculosis. Sputum analysis can involve both AFB staining and bacterial culture. In addition, a rapid molecular test (RMT) may identify bacterial strains and resistance to specific antibiotics.

Management

Cutaneous verrucous tuberculosis treatment follows general tuberculosis treatment guidelines, involving multiple antibiotics. Common drugs include rifampicin, isoniazid, pyrazinamide, and ethambutol, with streptomycin occasionally added. If the RMT or culture shows antibiotic resistance, alternative antibiotics may be used.

The treatment has two phases:

1. Intensive Phase: Reduces Mycobacterium tuberculosis levels quickly. This phase involves daily doses of rifampicin, isoniazid, pyrazinamide, and ethambutol for two months. Sometimes, streptomycin injections are added.
2. Continuation Phase: Completes bacterial eradication. This phase involves rifampicin and isoniazid, taken daily or three times a week for four months.

Cutaneous verrucous tuberculosis generally requires six months of treatment. Despite the number of medications, fixed-dose combination (FDC) pills are available. These contain four antibiotics for the intensive phase (excluding injectable streptomycin) and two for the continuation phase. The daily dosage depends on the patient’s body weight.

To manage cutaneous verrucous tuberculosis, patients must adhere to prescribed medication schedules, requiring commitment and discipline. Family members or close contacts can collaborate with healthcare providers as Directly Observed Treatment (DOT) supervisors, ensuring the medication is taken on time, at the correct dose, and not expelled by vomiting.

Antibiotics may cause side effects ranging from minor (red urine, nausea) to severe (hepatitis, allergic reactions, nerve issues). Consult a healthcare provider if you experience any side effects.

If diagnosed with multidrug-resistant tuberculosis (MDR-TB), the doctor may recommend alternative antibiotic treatments.

Complications

Complications from cutaneous verrucous tuberculosis are rare. When they occur, they may be cosmetic or cause discomfort in daily activities. However, the condition generally resolves on its own within a few years. Consult a doctor if lesions are bothersome or affect your quality of life.

Prevention

Preventing cutaneous verrucous tuberculosis involves:

1. BCG vaccination: recommended for newborns up to two months old. This vaccine introduces weakened Mycobacterium tuberculosis to stimulate an immune response against the bacteria.
2. Tuberculosis Screening: Screening includes symptom checks, identification, isolation, and management of tuberculosis cases to prevent spread, especially in immunocompromised individuals.
3. Immune Health Management: If you have HIV/AIDS or diabetes, regular treatment ensures adequate immunity to fight Mycobacterium tuberculosis. Blood sugar control in diabetics is crucial to prevent the spread of tuberculosis throughout the body, including the skin. If you take immunosuppressive drugs, your doctor may prescribe preventive antibiotics.

When to See a Doctor?

If you have warts in your hands, feet, arms, leg, or buttocks, you can consult a doctor. These warts can be caused by various germs, either viruses or bacteria. Doctors can do further examinations to find out the cause of the warts and provide advice on dealing with them. Doctors can also suggest to you other examinations to ensure there is no tuberculosis infection in your body.

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