Leaf rust of barley is considered a relatively minor disease in the United States. However, sporadic outbreaks have occurred in the southeastern and Midwestern regions of the country.

Pustules of leaf rust are small and circular, producing a mass of orange-brown powdery spores. They appear on the leaf sheaths and predominantly on the upper leaf surfaces. Heavily infected leaves die prematurely.

Citrus Black Spot is a fungal disease caused by Guignardia citricarpa. This Ascomycete fungus affects citrus plants throughout subtropical climates, causing a reduction in both fruit quantity and quality. Symptoms include both fruit and leaf lesions, the latter being critical to inter-tree dispersal. Strict regulation and management is necessary to control this disease since there are currently no citrus varieties that are resistant.

There is no resistance to Citrus Black Spot and once a tree has been infected there is no known cure causing tree removal to be the best option. Both Federal and State governments have recommended the following preventative measures.

To control "Guignardia citriparpa" fungicides like copper and/or strobilurins should be applied monthly from early May to the middle of September (in the northern hemisphere). Applications of the fungicides are recommended in early April (northern hemisphere) if that month has experienced more rainfall than usual resulting in the ideal conditions for citrus black spot to form.

Table 1. Recommended Chemical Controls for Citrus Black Spot

1)Lower rates can be used on smaller trees. Do not use less than minimum label rate.

2)Mode of action class for citrus pesticides from the Fungicide Resistance Action Committee (FRAC) 20111. Refer to ENY-624, "Pesticide Resistance and Resistance Management," in the 2012 Florida Citrus Pest Management Guide for more details.

3)Do not use more than 4 applications of strobilurin fungicides/season. Do not make more than 2 sequential applications of strobilurin fungicides.

Another method of control is to accelerate the leaf litter decomposition under the trees in citrus groves. Accelerating this decomposition reduces the chance for ascospore inoculation which generally takes place in the middle of March. There are three possible methods to hasten this decomposition. One method is the increase the mircrosprinkler irrigation in the grove to half an hour for at least five days of the week. This form of control should continue for about a month and a half. The second method is to apply urea or ammonium to the leaf litter. The last and final method to accelerate leaf decomposition is to apply lime or calcium carbonate to the litter. Urea, lime, and calcium carbonate reduce the number of fungal structures and spore production. Since the fungus requires wet conditions to thrive, air flow in the citrus grove should be maximized to reduce leaf wetness.

Along with these methods it is also important to get rid of debris such as fallen fruit or twigs in a manner that reduces the chances of infecting other plants. Citrus Black Spot can colonize and reproduce on dead twigs. To dispose of citrus debris it should either be heated to a minimum of 180℉ for two hours, incinerated, buried in a landfill, or fed to livestock. Plant trash should be moved with caution if at all to avoid spreading the infectious ascospores. Any trees that are infected with citrus black spot should be removed from the grove and disposed of. These trees must be removed because those that are declining and stressed will often have off season bloom. If there is more than one age of fruit present on the tree, it is possible for the asexual spores on the fruit to be transferred to new fruit, intensifying the disease. This off season blooming is often more problematic with Valencia oranges when old and new crops overlap.

Beet vascular necrosis and rot is a soft rot disease caused by the bacterium Pectobacterium carotovorum" subsp. "betavasculorum, which has also been known as "Pectobacterium betavasculorum" and "Erwinia carotovora" subsp. "betavasculorum". It was classified in the genus "Erwinia" until genetic evidence suggested that it belongs to its own group; however, the name Erwinia is still in use. As such, the disease is sometimes called Erwinia rot today. It is a very destructive disease that has been reported across the United States as well as in Egypt. Symptoms include wilting and black streaks on the leaves and petioles. It is usually not fatal to the plant, but in severe cases the beets will become hollowed and unmarketable. The bacteria is a generalist species which rots beets and other plants by secreting digestive enzymes that break down the cell wall and parenchyma tissues. The bacteria thrive in warm and wet conditions, but cannot survive long in fallow soil. However, it is able to persist for long periods of time in the rhizosphere of weeds and non-host crops. While it is difficult to eradicate, there are cultural practices that can be used to control the spread of the disease, such as avoiding injury to the plants and reducing or eliminating application of nitrogen fertilizer.

Wheat yellow rust ("Puccinia striiformis" f.sp. "tritici"), also known as stripe rust, is one of the three wheat rust diseases principally found in wheat grown in cooler environments. Such locations are generally associated with northern latitudes or cooler seasons.

The bacteria can survive in the rhizosphere of other crops such as tomato, carrots, sweet potato, radish, and squash as well as weed plants like lupin and pigweed, so it is very hard to get rid of it completely. When it is known that the bacterium is present in the soil, planting resistant varieties can be the best defense against the disease. Many available beet cultivars are resistant to "Pectobacterium carotovorum" subsp. "betavasculorum", and some examples are provided in the corresponding table. A comprehensive list is maintained by the USDA on the Germplasm Resources Information Network.

Even though some genes associated with root defense response have been identified, the specific mechanism of resistance is unknown, and it is currently being researched.

As R.P. Singh, J. Huerta-Espino, and A.P. Roelfs say in their (undated) comprehensive review of literature on the wheat rusts for UN FAO:

"Although Gadd first described stripe rust of wheat in 1777, it was not until 1896 that Eriksson and Henning (1896) showed that stripe rust resulted from a separate pathogen, which they named P. glumarum. In 1953, Hylander et al. (1953) revived the name P. striiformis."

As of November 2013, no identifiable cause for the disease had been found. Pathogenic bacteria did not seem to be present, and though the plague might be caused by a viral or fungal pathogen, no causal agent had been found. Each episode of plague might have a different cause.

Other possible causes of the condition that have been suggested include high sea temperatures, oxygen depletion and low salinity due to freshwater runoff. Research suggests that high water temperatures are indeed linked to the disease, increasing its incidence and virulence. The disease also seems more prevalent in sheltered waters than in open seas with much wave movement. One result of global warming is higher sea temperatures. There is a wave of unusually warm water along the west coast of the United States, which is where all of the sea stars are dying off. These may impact both on starfish and on echinoderm populations in general, and a ciliate protozoan parasite ("Orchitophrya stellarum") of starfish, which eats sperm and effectively emasculates male starfish, thrives at higher temperatures.

Research in 2014 showed that the cause of the disease is transmissible from one starfish to another and that the disease-causing agent is a microorganism in the virus-size range. The most likely candidate causal agent was found to be the sea star-associated densovirus (SSaDV), which was found to be in greater abundance in diseased starfish than in healthy ones.

The single-celled parasite's life cycle can be divided into three major phases. First, as a tomont, the parasite rests at the water's floor and divides into as many as 256 tomites. Second, these juvenile, motile tomites swim about in search of a fish host, meanwhile using photosynthesis to grow, and to fuel their search. Finally, the adolescent tomite finds and enters the slime coat of a host fish, dissolving and consuming the host's cells, and needing only three days to reach full maturity before detaching to become a tomont once more.

Velvet (in an aquarium environment) is usually spread by contaminated tanks, fish, and tools (such as nets or testing supplies). There are also rare reports of frozen live foods (such as bloodworms) containing dormant forms of the species. Frequently, however, the parasite is endemic to a fish, and only causes a noticeable "outbreak" after the fish's immune system is compromised for some other reason. The disease is highly contagious and can prove fatal to fish.

In 2014, Point Defiance Zoo and Aquarium lost more than half of its 369 sea stars, and by September 2015 they numbered fewer than 100. The aquarium treated its affected sea stars with antibiotics in 2014, which proved effective. Although a mechanism is still unknown, evidence suggests that a single mutation in the elongation factor 1-alpha locus in "Pisaster ochraceus" may be associated with reduced mortality.

While the condition has been seen in over 60 breeds of dog (including cross breeds), certain breeds have been found to be more susceptible than others to sebaceous adenitis:

- American Akita and Akita Inu

- Standard Poodle

- Vizsla

- English Springer Spaniel

- Chow Chow

- Samoyed

- Weimaraner

- Havanese

Breeds also mentioned in scientific literature as having some susceptibility include:

- German Shepherd

- Dachshund

- Old English Sheepdog

- Lhasa Apso

- Boxer

- Collie

- Toy Poodle

- Mixed-breeds

Sebaceous adenitis has no sex-predisposition. Sebaceous adenitis also occurs in cats, rabbits and horses.

Schamberg's disease is caused by leaky blood vessels near the surface of the skin, capillaries, which allow red blood cells to slip through into the skin. The red blood cells in the skin then fall apart and release their iron, which is released from hemoglobin. The iron causes a rust color and this accounts for the orange tint of the rash that can be seen on the skin. The underlying cause of the leaky blood vessels is not known, but researchers are suggesting that there could be some potential triggers. Some possible triggers include viral infection, a hypersensitivity to some agent, and interaction of some medications, such as thiamine and aspirin. Even though there is no correlation with genetics, there have been a few cases where few people in a family had this condition.

Although the cause of capillary inflammation is unknown, certain preventive measures can be taken. Doctors may prescribe medications that enhance the circulation of blood, which can keep blood vessels strong and healthy. Daily intake of vitamin C has proven to be a natural home remedy that can prevent the onsite of any disease or infection. Doctors always recommend that their patients monitor what they eat because their diet could be a possible factor that contributes to this condition. A healthy body that receives nutritious meals is more likely to have a healthy life that does not revolve around a lot of health problems.

Schamberg's disease, (also known as "progressive pigmentary dermatosis of Schamberg", "purpura pigmentosa progressiva" (PPP), and "Schamberg's purpura") is a chronic discoloration of the skin found in people of all ages, usually affecting the legs. It slowly spreads throughout the body, and is most common in males. It is named after Jay Frank Schamberg, who described it in 1901. There is no known cure for this disease and it is not a life-threatening condition. The skin lesions may cause itching, which can be treated by applying cortisone cream. The cortisone cream will only help with the itching and the discoloration of the skin will remain, which may cause a cosmetic concern in the future. Schamberg's disease is usually asymptomatic meaning that it shows no signs of this condition, except for the discoloration of the skin. This condition is caused by leaky blood vessels, where red blood cells escape near the surface of skin and release its iron into the surrounding tissue. The cause of the leaky capillaries is unknown.

Commonly used dietary supplements include:

- Omega-6 fatty acids (e.g., safflower or sunflower oil)

- Omega-3 fatty acids (e.g., fish oils)

- Vitamin A.

Lichen aureus (also known as "lichen purpuricus") is a skin condition characterized by the sudden appearance of one or several golden or rust-colored, closely packed macules or lichenoid papules.

Gougerot–Blum syndrome (also known as "pigmented purpuric lichenoid dermatitis", and "pigmented purpuric lichenoid dermatitis of Gougerot and Blum") is a variant of pigmented purpuric dermatitis, a skin condition characterized by minute, rust-colored to violaceous, lichenoid papules that tend to fuse into plaques of various hues. Relative to other variants, it is characterized clinically by a male predominance, pruritus, with a predilection for the legs, and histologically, it features a densely cellular lichenoid infiltrate.

It was characterized in 1925.

Gougerot–Blum syndrome is named after the French dermatologists Henri Gougerot (1881–1955) and Paul Blum (1878–1933).

Exposure of spermatozoa to lifestyle, environmental and/or occupational hazards may increase the risk of aneuploidy. Cigarette smoke is a known aneugen (aneuploidy inducing agent). It is associated with increases in aneuploidy ranging from 1.5 to 3.0-fold. Other studies indicate factors such as alcohol consumption, occupational exposure to benzene, and exposure to the insecticides fenvalerate and carbaryl also increase aneuploidy.

There is no good evidence that a mother's diet during pregnancy, the formula used, or breastfeeding changes the risk. There is tentative evidence that probiotics in infancy may reduce rates but it is insufficient to recommend its use.

People with eczema should not get the smallpox vaccination due to risk of developing eczema vaccinatum, a potentially severe and sometimes fatal complication.

Most cases are well managed with topical treatments and ultraviolet light. About 2% of cases are not. In more than 60% of young children, the condition subsides by adolescence.

The medical condition of being overweight or obesity is defined as "abnormal or excessive fat accumulation that may impair health". It is measured through the Body Mass Index (BMI), defined as a person's weight, in kilograms, divided by the square of the person's height, in meters. If an individual has a BMI of 25–29, he or she is overweight. Having a BMI of 30 or more means an individual is obese. The greater the BMI, the greater the risk of chronic diseases as a result of obesity. These diseases include cardiovascular diseases, diabetes, musculoskeletal disorders, cancer, and premature death.

Down syndrome, a trisomy of chromosome 21, is the most common anomaly of chromosome number in humans. The majority of cases results from nondisjunction during maternal meiosis I. Trisomy occurs in at least 0.3% of newborns and in nearly 25% of spontaneous abortions. It is the leading cause of pregnancy wastage and is the most common known cause of mental retardation. It is well documented that advanced maternal age is associated with greater risk of meiotic nondisjunction leading to Down syndrome. This may be associated with the prolonged meiotic arrest of human oocytes potentially lasting for more than four decades.

Some studies reported up to 80% of patients with irritable bowel syndrome (IBS) have SIBO (using the hydrogen breath test). Subsequent studies demonstrated statistically significant reduction in IBS symptoms following therapy for SIBO.

There is a lack of consensus however, regarding the suggested link between IBS and SIBO. Other authors concluded that the abnormal breath results so common in IBS patients do not suggest SIBO, and state that "abnormal fermentation timing and dynamics of the breath test findings support a role for abnormal intestinal bacterial distribution in IBS." There is general consensus that breath tests are abnormal in IBS; however, the disagreement lies in whether this is representative of SIBO. More research is needed to clarifiy this possible link.

Porphyria cutanea tarda has a prevalence estimated at approximately 1 in 10,000. An estimated 80% of porphyria cutanea tarda cases are sporadic. The exact frequency is not clear because many people with the condition never experience symptoms and those that do are often misdiagnosed with anything ranging from idiopathic photodermatitis and seasonal allergies to hives.