Did you know there is a disease called skin tuberculosis?
The professor shared a case of skin tuberculosis on Weibo before, but many people in the comment area had never heard of this disease.
Actually, Mycobacterium tuberculosis can infect anywhere except hair and nails. If the lung is infected, it is called pulmonary tuberculosis, if the kidney is infected, it is called renal tuberculosis, and if it is infected with the skin, it is called skin tuberculosis.
While pulmonary TB infection is the most common of all sites, cutaneous TB infection is also uncommon and can be underdiagnosed.
Today, Xiao Ming is here to talk to you about skin tuberculosis~
History of Tuberculosis
As far back as ancient Egypt and as far back as modern times, there are traces of tuberculosis. Some people believe that Mycobacterium tuberculosis is the pathogenic microorganism that causes the most deaths in humans.
Unlike the panic caused by other diseases, the history of tuberculosis is a little romantic.
In ancient and modern Chinese and foreign literary works, there are many descriptions of tuberculosis. For example, in “A Dream of Red Mansions”, the delicate sister Lin walked three steps and panted four times.
To be honest, Xiao Ming had a strong desire to protect this character when he was watching TV series.
In Europe in the 18th century, tuberculosis was fashionable for a period of time, and even took the initiative to get tuberculosis, because the sick person was pale and thin, which was in line with the mainstream aesthetics at that time ( Sick and beautiful).
Poet Byron said, “If you want to die, you want to die of tuberculosis.”
Xiao Ming wants to say that if Byron knew about skin tuberculosis, he would definitely swallow this sentence back!
The first report of cutaneous tuberculosis was in 1826, when Laennec (inventor of the stethoscope) described the first case of cutaneous tuberculosis, which was then mistaken for tumor.
It wasn’t until 1882, when Mycobacterium tuberculosis was formally discovered, that it was detected in skin lesions that the fog of cutaneous tuberculosis was lifted.
Skin tuberculosis is a skin disease caused by Mycobacterium tuberculosis, mostly human tuberculosis and occasionally bovine tuberculosis Bacillus.
Image source veer
Skin tuberculosis infection routes include exogenous and endogenous.
The former is mainly infected directly through minor damage to the skin and mucous membranes, while the latter is caused by existing tuberculosis lesions in the body organs or tissues through the blood, lymphatic system or direct infection Spreads to skin.
Extrapulmonary TB (tuberculosis other than pulmonary TB) accounted for 15% of the 7 million new cases in 2018, while cutaneous TB accounted for all extrapulmonary manifestations, according to WHO 2019 data Less than 2%, or about 20,000.
This is just the number of confirmed cases, and there are potential misdiagnoses and missed diagnoses.
The Nutshell Patient has published the experience of a patient with cutaneous tuberculosis.
From symptomatic consultation to diagnosis, it took her two months to travel to many hospitals and to see doctors in many departments such as vascular surgery, dermatology, rheumatology and immunology, and thoracic surgery. Finally diagnosed with skin tuberculosis, eat the correct treatment drugs.
She teased herself: The disease is not yet optimistic, but the registration ability has increased a lot.
Some people may ask, isn’t it a doctor’s problem to see the wrong disease?
It is undeniable that misdiagnosis has something to do with the physician’s personal experience, but also with the complexity of the symptoms of the disease.
Symptoms and Classification
Skin lesions of cutaneous tuberculosis can occur all over the body, and different types of skin tuberculosis skin lesions have different predilection sites.
The types of skin lesions vary, mainly including nodules, ulcers, verrucous plaques, papules, necrosis/strong> etc. Without treatment, the course of the disease can be prolonged for years or decades.
Skin tuberculosis can be divided into three categories according to the route of transmission: Exogenous vaccination (primary inoculation tuberculosis, verrucous skin tuberculosis), exogenous vaccination >Proximity dissemination (scrofula cutaneous tuberculosis, oral skin tuberculosis) and hematogenous dissemination (acute miliary tuberculosis, lupus vulgaris).
The most common are verrucous cutaneous tuberculosis and lupus vulgaris.
Verrucous cutaneous tuberculosis
Verrucous skin tuberculosis accounts for about 40% of skin tuberculosis, and it occurs in acral, such as finger, back of hand, calf, etc. .
Lesses are usually isolated and often appear as 1-5 cm in diameter, violet or reddish-brown, painless, verrucous plaques.
Lupus vulgaris accounts for about 10% to 15% of cutaneous tuberculosis and is most commonly found on the face, followed by the neck, buttocks, and extremities .
The symptoms of lupus vulgaris are variable and may begin as a group of discrete red-brown papules that gradually coalesce to form indolent, Asymptomatic plaques. Hypertrophic, ulcerative, or neoplastic lupus vulgaris may also occur.
Diagnosis and Treatment
To diagnose cutaneous tuberculosis, symptoms alone are not enough, plus skin biopsy and histopathology, tuberculin test, bacterial culture, etc. Laboratory tests can confirm whether it is skin tuberculosis.
Similar to pulmonary tuberculosis, the treatment of skin tuberculosis is based on oral anti-tuberculosis drugs (rifampicin, isoniazid, pyrazinamide, etc.) Symptoms mostly subside after treatment.
Image source reference 4
Early, smaller lesions of lupus vulgaris or verrucous cutaneous tuberculosis may also be surgical excision.
The best way to prevent skin tuberculosis is to vaccinate against BCG. The “scar” on your arm is a sign of vaccination.
However, there is a small chance of infection after vaccination.
And the BCG vaccine is made from a live attenuated strain of Mycobacterium bovis, very few people experience dermatological complications such as local tissue reactions, ulcers, and abscess formation when vaccinated. etc., there are also scrofula cutaneous tuberculosis, lupus vulgaris and so on.
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We are usually the denominator of epidemiological statistics and rarely the numerator, and it is always good to know a little more about the disease whenever we are.
 Zhao Bian, editor-in-chief. Chinese Clinical Dermatology 2nd Edition [M]. Nanjing: Jiangsu Science and Technology Press, 2017.04.
 Editor-in-chief Zhang Xuejun. Dermatology 8th Edition [M]. Beijing: People’s Health Publishing House, 2013.03.
 Evangeline B Handog, MDMaria Juliet E Macarayo, MD.Cutaneous manifestations of tuberculosis.UpToDate
 Zhou Lin, Shen Xinghua. A case of skin tuberculosis[J]. Journal of Tuberculosis and Lung Disease, 2022,3(01):85-86.