Spirochaetales is an order of bacteria that are characterized by their unique spiral or corkscrew shape. This shape allows them to move in a flexing, twisting motion, which can be quite rapid. They are gram-negative, meaning they do not retain crystal violet stain in the Gram staining method, and they have a unique structure with endoflagella (also known as axial filaments) located inside their outer membrane.

The Spirochaetales order includes several families and genera of bacteria, some of which are free-living, while others are parasitic or symbiotic. The parasitic spirochetes can cause various diseases in humans and animals. For example, Treponema pallidum is the causative agent of syphilis, a serious sexually transmitted infection. Another species, Borrelia burgdorferi, causes Lyme disease, which is transmitted to humans through the bite of infected black-legged ticks.

It's important to note that spirochetes are a diverse group with varying characteristics and pathogenic potential. While some species can cause significant harm, others are not associated with diseases and play essential roles in various ecosystems.

A medical definition of "ticks" would be:

Ticks are small, blood-sucking parasites that belong to the arachnid family, which also includes spiders. They have eight legs and can vary in size from as small as a pinhead to about the size of a marble when fully engorged with blood. Ticks attach themselves to the skin of their hosts (which can include humans, dogs, cats, and wild animals) by inserting their mouthparts into the host's flesh.

Ticks can transmit a variety of diseases, including Lyme disease, Rocky Mountain spotted fever, anaplasmosis, ehrlichiosis, and babesiosis. It is important to remove ticks promptly and properly to reduce the risk of infection. To remove a tick, use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick, as this can cause the mouthparts to break off and remain in the skin. After removing the tick, clean the area with soap and water and disinfect the tweezers.

Preventing tick bites is an important part of protecting against tick-borne diseases. This can be done by wearing protective clothing (such as long sleeves and pants), using insect repellent containing DEET or permethrin, avoiding wooded and brushy areas with high grass, and checking for ticks after being outdoors.

Lyme disease is not a "medical definition" itself, but it is a medical condition named after the town of Lyme, Connecticut, where it was first identified in 1975. Medical definitions for this disease are provided by authoritative bodies such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC). According to the CDC, Lyme disease is a "infection caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of infected black-legged ticks."

The WHO defines Lyme borreliosis (LB), also known as Lyme disease, as "an infectious disease caused by spirochetes of the Borrelia burgdorferi sensu lato complex. It is transmitted to humans through the bite of infected Ixodes spp. ticks."

Both definitions highlight that Lyme disease is a bacterial infection spread by tick bites, specifically from black-legged ticks (Ixodes scapularis in the United States and Ixodes pacificus on the Pacific Coast) or deer ticks (Ixodes ricinus in Europe). The primary cause of the disease is the spirochete bacterium Borrelia burgdorferi.

Erythema chronicum migrans (ECM) is a type of skin rash that is commonly associated with early Lyme disease. It is usually the first sign of infection after a tick bite and is caused by the bacterium Borrelia burgdorferi. The rash typically appears within 3-30 days after the tick bite and starts as a red, flat or slightly raised spot at the site of the bite. Over several days or weeks, the redness expands, forming a circular or oval-shaped rash that can be up to 12 inches in diameter. The center of the rash may clear, giving it a "bull's-eye" appearance.

ECM is usually accompanied by symptoms such as fatigue, fever, headache, and muscle and joint pain. It is important to note that not all people with Lyme disease will develop ECM, and its absence does not necessarily mean that the person does not have Lyme disease. If you suspect that you may have been bitten by a tick and are experiencing symptoms of Lyme disease, it is important to seek medical attention promptly.

Erythema is a term used in medicine to describe redness of the skin, which occurs as a result of increased blood flow in the superficial capillaries. This redness can be caused by various factors such as inflammation, infection, trauma, or exposure to heat, cold, or ultraviolet radiation. In some cases, erythema may also be accompanied by other symptoms such as swelling, warmth, pain, or itching. It is a common finding in many medical conditions and can vary in severity from mild to severe.

Larva migrans is a parasitic infection caused by the larval stage of certain nematode (roundworm) species. The term "larva migrans" is used to describe two distinct clinical syndromes: cutaneous larva migrans and visceral larva migrans.

1. Cutaneous Larva Migrans (CLM): Also known as creeping eruption, it is caused by the hookworm species that typically infect dogs and cats (Ancylostoma braziliense, Ancylostoma caninum). The larvae penetrate human skin, usually through bare feet in contact with contaminated soil or sand, and cause an intensely pruritic (itchy) serpiginous (snake-like) track as they migrate under the skin.

2. Visceral Larva Migrans (VLM): It is caused by the migration of larvae from certain roundworm species, such as Toxocara spp., which primarily infect canids (dogs and related animals). Humans become accidental hosts when they ingest embryonated eggs present in contaminated soil, water, or undercooked meat. The larvae then migrate through various organs, causing inflammation and damage to tissues. VLM often affects the liver, lungs, eyes, and less commonly the central nervous system. Symptoms can vary widely depending on the organs involved but may include fever, cough, abdominal pain, and eye inflammation.

It is important to note that these infections are not transmitted from person-to-person. Preventive measures include wearing shoes in areas with contaminated soil, washing hands thoroughly after contact with soil or pets, cooking meat properly, and avoiding the ingestion of dirt or sand by young children.

Visceral Larva Migrans is a parasitic infection caused by the migration of the larval stage of certain nematode roundworms, such as Toxocara spp. (most commonly Toxocara canis or Toxocara cati), through the tissues of the host. The larvae are ingested, usually through the consumption of contaminated soil, water, or undercooked meat, and then penetrate the intestinal wall, entering the bloodstream and migrating to various organs, including the liver, lungs, central nervous system, and eyes. This condition is more commonly seen in children due to their higher likelihood of engaging in pica (the consumption of soil or other non-food items) and having close contact with pets that may carry these parasites. Symptoms can vary widely depending on the organs involved but often include fever, coughing, wheezing, abdominal pain, and skin rashes. In severe cases, it can lead to potentially life-threatening complications such as blindness or neurological damage. Diagnosis typically involves a combination of clinical presentation, imaging studies, and laboratory tests, such as serology or stool examination for parasite eggs. Treatment usually consists of anthelmintic medications to eliminate the parasites and supportive care to manage symptoms.

Erythema nodosum is a type of inflammation that occurs in the fatty layer of the skin, causing painful, red or purple bumps (nodules) to form. It is a type of panniculitis, which refers to any condition that causes inflammation of the fatty layer of tissue beneath the skin.

Erythema nodosum is often associated with a variety of underlying conditions, such as infections (e.g., streptococcus, tuberculosis), medications (e.g., sulfa drugs, oral contraceptives), inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis), and pregnancy.

The bumps associated with erythema nodosum typically appear on the shins, ankles, knees, or other areas of the legs, although they can also occur on the arms, hands, or face. The bumps may be tender to the touch, warm, and swollen, and they may cause pain or discomfort when walking or standing for prolonged periods.

In most cases, erythema nodosum resolves on its own within a few weeks to several months, although symptoms can be managed with medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. Treating the underlying condition is also important for resolving erythema nodosum and preventing recurrences.

Benign migratory glossitis, also known as geographic tongue, is a medical condition characterized by the presence of denuded, irregularly shaped smooth patches on the dorsum of the tongue. These patches are usually red and often have a white or yellow border. The condition is called "benign migratory" because it is not harmful or cancerous, and the lesions can change in size, shape, and location over time.

The exact cause of benign migratory glossitis is unknown, but it has been associated with several factors such as stress, nutritional deficiencies (particularly vitamin B deficiency), allergies, and family history. The condition can be asymptomatic or may cause symptoms such as burning sensation, pain, or altered taste.

Treatment of benign migratory glossitis is usually not necessary unless the patient experiences discomfort or other symptoms. In such cases, topical anesthetics, antihistamines, or corticosteroids may be prescribed to alleviate the symptoms. However, if the underlying cause can be identified and addressed (such as nutritional deficiencies), the condition may improve on its own.

Ascaridoidea is a superfamily of parasitic nematode roundworms that includes several medically important genera such as Ascaris, Toxocara, and Baylisascaris. These worms have a complex life cycle involving intermediate hosts like insects or mammals, and definitive hosts such as humans or other animals.

In humans, the most common species of Ascaridoidea are Ascaris lumbricoides (also known as "human roundworm") and Toxocara canis (dog roundworm) or Toxocara cati (cat roundworm). Infection with these parasites typically occurs through ingestion of contaminated food, water, or soil.

Ascaris lumbricoides infection, known as ascariasis, can cause symptoms such as abdominal pain, nausea, vomiting, and diarrhea. Severe infections may lead to intestinal obstruction, malnutrition, or impaired growth in children.

Toxocara infection, also called toxocariasis, can result in visceral larva migrans (VLM) or ocular larva migrans (OLM), depending on the organs affected. VLM may cause fever, cough, wheezing, and hepatomegaly, while OLM can lead to vision loss or eye inflammation.

Preventive measures include proper hygiene practices, such as handwashing, cooking food thoroughly, and avoiding contact with contaminated soil or feces. In some cases, medication may be necessary to treat these infections.

Acrodermatitis is a term that describes several inflammatory skin conditions characterized by redness, swelling, and blistering that typically affect the hands, feet, and face. The medical definition of acrodermatitis includes various subtypes, each with its own specific causes and symptoms. Here are some of the most common forms of acrodermatitis:

1. Acrodermatitis enteropathica: A rare inherited disorder caused by a deficiency in zinc absorption. Symptoms include redness, swelling, blistering, and crusting around the mouth, eyes, and genitals, as well as the hands and feet.
2. Acrodermatitis continua of Hallopeau: A rare chronic inflammatory skin condition that affects the fingertips and toes. Symptoms include redness, swelling, blistering, and crusting, which can lead to nail deformities and loss.
3. Gianotti-Crosti syndrome (acrodermatitis papulosa): A viral exanthem that typically affects children between 6 months and 15 years of age. Symptoms include red, raised bumps on the face, buttocks, and extremities, which can be itchy and painful.
4. Pustular acrodermatitis: A rare skin condition characterized by pustules (pus-filled bumps) that form on the palms of the hands and soles of the feet. Symptoms may also include fever, chills, and fatigue.
5. Infantile acrodermatitis: A rare inflammatory skin disorder that affects infants and young children. Symptoms include redness, swelling, and blistering around the mouth, eyes, and genitals, as well as the hands and feet.

Treatment for acrodermatitis depends on the underlying cause of the condition. In some cases, topical creams or ointments may be sufficient to manage symptoms, while in others, systemic treatments such as antibiotics or immunosuppressive drugs may be necessary.

"Toxocara canis" is a species of roundworm that primarily infects canids, such as dogs and foxes. The adult worms live in the intestines of the host animal, where they lay eggs that are passed in the feces. These eggs can then mature and become infective to other animals, including humans, if they ingest them.

In humans, infection with "Toxocara canis" can cause a range of symptoms known as toxocariasis, which can include fever, coughing, wheezing, rash, and abdominal pain. In severe cases, the larvae of the worm can migrate to various organs in the body, including the eyes, leading to potentially serious complications.

Preventive measures for "Toxocara canis" infection include good hygiene practices, such as washing hands after handling pets or coming into contact with soil that may contain infected feces, and regular deworming of pets.

The Borrelia burgdorferi group, also known as the Borrelia burgdorferi sensu lato (s.l.) complex, refers to a genetically related group of spirochetal bacteria that cause Lyme disease and other related diseases worldwide. The group includes several species, with Borrelia burgdorferi sensu stricto (s.s.), B. afzelii, and B. garinii being the most common and best studied. These bacteria are transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis in the United States and Ixodes pacificus on the West Coast; Ixodes ricinus in Europe).

Lyme disease is a multisystem disorder that can affect the skin, joints, nervous system, and heart. Early symptoms typically include a characteristic expanding rash called erythema migrans, fever, fatigue, headache, and muscle and joint pain. If left untreated, the infection can spread to other parts of the body and cause more severe complications, such as arthritis, neurological problems, and carditis.

Diagnosis of Lyme disease is based on a combination of clinical symptoms, exposure history, and laboratory tests. Treatment usually involves antibiotics, such as doxycycline, amoxicillin, or ceftriaxone, and is generally most effective when initiated early in the course of the illness. Preventive measures, such as using insect repellent, checking for ticks after being outdoors, and promptly removing attached ticks, can help reduce the risk of Lyme disease and other tick-borne infections.

Ascaridida infections are caused by roundworms belonging to the order Ascaridida, which includes several species that can infect humans and animals. The most common species that infects humans is Ascaris lumbricoides, also known as the human roundworm. Other species that can cause infection in humans include Toxocara spp., Baylisascaris procyonis, and Ascaris suum (the pig roundworm).

Infection with these parasites typically occurs through ingestion of contaminated food or water containing eggs or larvae. The larvae hatch in the small intestine and then migrate through the body to various organs, including the liver, lungs, and eyes, where they can cause damage. After several weeks, the larvae return to the small intestine, where they mature into adult worms and begin producing eggs.

Symptoms of ascariasis (infection with Ascaris lumbricoides) can vary depending on the severity of the infection and the location of the worms in the body. Mild infections may cause no symptoms or only mild gastrointestinal symptoms such as abdominal pain, nausea, and diarrhea. More severe infections can lead to intestinal obstruction, malnutrition, and other complications.

Infection with Toxocara spp. can cause a condition called visceral larva migrans, which is characterized by fever, cough, rash, and liver enlargement. Ocular larva migrans can occur when the larvae migrate to the eye, causing inflammation and potentially leading to vision loss.

Baylisascaris procyonis infection can cause a similar condition called neural larva migrans, which can lead to neurological symptoms such as seizures, muscle weakness, and paralysis.

Prevention of Ascaridida infections involves practicing good hygiene, including washing hands thoroughly with soap and water after using the toilet or handling soil or contaminated objects. Proper cooking and cleaning of food can also help prevent infection. In areas where ascariasis is common, treatment of human waste and improvement of sanitation infrastructure can help reduce transmission.

Toxocara is a type of parasitic roundworm that belongs to the genus Toxocara. The two most common species that infect humans are Toxocara canis and Toxocara cati, which are primarily found in dogs and cats, respectively.

Humans can become infected with Toxocara through accidental ingestion of contaminated soil or sand that contains the eggs of the parasite. This can occur when people come into contact with infected animal feces and then touch their mouths without properly washing their hands. Children are particularly at risk of infection due to their frequent hand-to-mouth behaviors and tendency to play in environments where the eggs may be present.

In humans, Toxocara infection can cause a range of symptoms known as toxocariasis. The most common form is visceral larva migrans (VLM), which occurs when the parasite's larvae migrate through various organs in the body, causing inflammation and damage. Symptoms of VLM may include fever, fatigue, coughing, wheezing, abdominal pain, and liver enlargement.

Another form of toxocariasis is ocular larva migrans (OLM), which occurs when the parasite's larvae migrate to the eye, causing inflammation and potentially leading to vision loss. Symptoms of OLM may include eye pain, redness, blurred vision, and light sensitivity.

Preventive measures for Toxocara infection include washing hands thoroughly after handling animals or coming into contact with soil, covering sandboxes when not in use, and cooking meat thoroughly before eating. Treatment for toxocariasis typically involves anti-parasitic medications such as albendazole or mebendazole, which can help kill the parasite's larvae and reduce symptoms.

'Borrelia burgdorferi' is a species of spirochete bacteria that is the primary cause of Lyme disease in humans. The bacteria are transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis in the northeastern, midwestern, and eastern parts of the United States; Ixodes pacificus on the Pacific Coast).

The bacterium was first identified and named after Willy Burgdorfer, who discovered the spirochete in the mid-1980s. The infection can lead to a variety of symptoms, including fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, the infection can spread to joints, the heart, and the nervous system, leading to more severe complications.

Antibiotic treatment is usually effective in eliminating the bacteria and resolving symptoms, especially when initiated early in the course of the disease. However, some individuals may experience persistent symptoms even after treatment, a condition known as post-treatment Lyme disease syndrome (PTLDS). The exact cause of PTLDS remains unclear, with ongoing research investigating potential factors such as residual bacterial infection, autoimmune responses, or tissue damage.