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Mycobacterial cervical lymphadenitis

Mycobacterial cervical lymphadenitis is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Mycobacterial cervical lymphadenitis rather than just read about it. In short: The disease mycobacterial cervical lymphadenitis, also known historically as scrofula and the king's evil, involves a lymphadenitis of the cervical (neck) lymph nodes associated with tuberculosis as well as nontuberculous (atypical) mycobacteria such as Mycobacterium marinum. Disease Scrofula is the term used for lymphadenopathy of the neck, usually as a result of an infection in the lymph nodes known as lymphadenit…

Mycobacterial cervical lymphadenitis — main illustration
Mycobacterial cervical lymphadenitis — illustration

Key takeaways

  • Mycobacterial cervical lymphadenitis belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Mycobacterial cervical lymphadenitis to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Mycobacterial cervical lymphadenitis from memory before moving on to harder problems.

Reference excerpt

The disease mycobacterial cervical lymphadenitis, also known historically as scrofula and the king's evil, involves a lymphadenitis of the cervical (neck) lymph nodes associated with tuberculosis as well as nontuberculous (atypical) mycobacteria such as Mycobacterium marinum.

Disease Scrofula is the term used for lymphadenopathy of the neck, usually as a result of an infection in the lymph nodes known as lymphadenitis. It can be caused by tuberculous or nontuberculous mycobacteria. About 95% of the scrofula cases in adults are caused by Mycobacterium tuberculosis, most often in immunocompromised patients (about 50% of cervical tuberculous lymphadenopathy). In immunocompetent children, scrofula is often caused by atypical mycobacteria (Mycobacterium scrofulaceum) and other nontuberculous mycobacteria (NTM). Unlike the adult cases, only 8% of cases in children are tuberculous. With the stark decrease of tuberculosis in the second half of the 20th century, scrofula became a less common disease in adults, but remained common in children. With the appearance of HIV/AIDS, however, it has shown a resurgence, and can affect patients at all stages of the disease.

Signs and symptoms The most usual signs and symptoms are the appearance of a chronic, painless mass in the neck, which is persistent and usually grows with time. The mass is referred to as a "cold abscess", because there is no accompanying local color or warmth and the overlying skin acquires a violaceous (bluish-purple) color. NTM infections do not show other notable constitutional symptoms, but scrofula caused by tuberculosis is usually accompanied by other symptoms of the disease, such as fever, chills, malaise and weight loss in about 43% of the patients. As the lesion progresses, skin becomes adhered to the mass and may rupture, forming a sinus and an open wound. The fatal outcome some patients experienced in earlier times was due to a cheese-like presentation of the lungs and the King's Evil lesions. It was also associated with pulmonary tuberculosis. Cervical lymphadenitis is commonly caused by an infection of mycobacteria in the head region. This disease is very inconsistent; cases can have different laboratory findings. Sometimes the disease can occur due to tuberculosis disease. However it is vital that, on a case-by-case basis, it is determined whether the cause is tuberculous or nontuberculous mycobacteria, as treatment often differs between the two forms.

Diagnosis Diagnosis is usually performed by needle aspiration biopsy or excisional biopsy of the mass and the histological demonstration of stainable acid-fast bacteria in the case of infection by M. tuberculosis (Ziehl–Neelsen stain), or the culture of NTM using specific growth and staining techniques.

Pathology The classical histologic pattern of scrofula features caseating granulomas with central acellular necrosis (caseous necrosis) surrounded by granulomatous inflammation with multinucleated giant cells. Although tuberculous and non tuberculosis lymphadenitis are morphologically identical, the pattern is somewhat distinct from other causes of bacterial lymphadenitis.

Treatment

17th century King's Evil, as the disease was historically called, was known as a frequent disorder in the 17th century, and was believed to be caused by bad blood coagulating in spongy organs such as the thyroid and the lymph nodes. Physicians also believed the disease could be inherited and could result from parents' untreated venereal infections. The treatment for mycobacterial cervical lymphadenitis consisted primarily of small incisions to remove the surrounding soft tissue and/or the abnormal mass. Until the 18th century, many doctors thought the only way to cure the disease was to be touched by a member of a royal family. In both France and England, the kings, who were thought to have inherited a miraculous power to cure the illness, touched crowds of infected people. The 'touchings' began in France during the reign of King Philip I (1060–1108) and in England during the reign of King Henry I (1100–1135). This act of public healing by powerful kings and royal family members encouraged the nickname "King's Evil". After the touching, the sovereign presented the affected person with an angel on a gold-plated coin that was to be hung around the infected person by a ribbon. This was used as a way of warding off the disease. This coin could have weighed as much as 5 grams and was considered a touch piece of great value. At age three the English lexicographer Samuel Johnson, for example, was treated for scrofula in this way, touched by Queen Anne and presented with a piece of gold, unfortunately to no effect. The royal touch and surgical removal were not the only methods of healing employed: Scrophularia nodosa (common name: Figwort), which has nodular roots that resemble the swollen lymph nodes of the affected, was thought to be useful in treating the disease, according to the doctrine of signatures – the plant being hung around the neck of the affected. Figwort does, in fact, contain compounds that can help decrease inflammation, irritation and discomfort.

… excerpt ends here. Continue reading the full article.

Illustrations

Mycobacterial cervical lymphadenitis illustration

Worked examples

Example 1 — a first encounter with Mycobacterial cervical lymphadenitis

Start with the simplest possible case. Write down what Mycobacterial cervical lymphadenitis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Mycobacterial cervical lymphadenitis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Mycobacterial cervical lymphadenitis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Mycobacterial cervical lymphadenitis

In research
Mycobacterial cervical lymphadenitis appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Mycobacterial cervical lymphadenitis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Mycobacterial cervical lymphadenitis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anne, Queen of Great Britain, Henry Benedict Stuart, Henry IV of France, so understanding it makes those chapters shorter.
In everyday life
Look for Mycobacterial cervical lymphadenitis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Mycobacterial cervical lymphadenitis in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Mycobacterial cervical lymphadenitis means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Mycobacterial cervical lymphadenitis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mycobacterial cervical lymphadenitis in simple terms?

The disease mycobacterial cervical lymphadenitis, also known historically as scrofula and the king's evil, involves a lymphadenitis of the cervical (neck) lymph nodes associated with tuberculosis as well as nontuberculous (atypical) mycobacteria such as Mycobacterium marinum. Disease Scrofula is th…

Why does Mycobacterial cervical lymphadenitis matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Mycobacterial cervical lymphadenitis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Mycobacterial cervical lymphadenitis.

Tags

  • Anne, Queen of Great Britain
  • Henry Benedict Stuart
  • Henry IV of France
  • Henry VI of England
  • Mycobacterium-related cutaneous conditions
  • Tuberculosis

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