Diagnosis is based on the characteristic appearance of non-healing raised, scaling lesions that may ulcerate and become secondarily infected with organisms such as "Staphylococcus aureus", in someone who has returned from an endemic area.

The gold standard for diagnosis is PCR (polymerase chain reaction) helps DNA polymerase to create new strands of DNA equivalent to template given.

The best treatment for cutaneous leishmaniasis is not known. Treatments that work for one species of leishmania may not work for another; it is recommended that advice of a tropical medicine or geographical medicine specialist be sought. Ideally, every effort should be made to establish the species of leishmania by molecular techniques (PCR) prior to starting treatment. In the setting of a developing country, there is often only one species present in a particular locality, so it is usually unnecessary to speciate every infection. Unfortunately, leishmaniasis is an orphan disease in developed nations, and almost all the current treatment options are toxic with significant side effects. The most sound treatment for cutaneous leishmaniasis thus far is prevention.

- "Leishmania major" :"L. major" infections are usually considered to heal spontaneously and do not require treatment, but there have been several reports of severe cases caused by "L. major" in Afghanistan. In Saudi Arabia, a six-week course of oral fluconazole 200 mg daily has been reported to speed up healing. In a randomized clinical trial from Iran, fluconazole 400 mg daily was shown to be significantly more effective than fluconazole 200 mg daily in the treatment of cutaneous leishmaniasis.

- "Leishmania braziliensis" :Treatment with pentavalent antimonials or amphotericin is necessary, because of the risk of developing disfiguring mucocutaneous lesions.

- "Leishmania infantum" :"L. infantum" causes cutaneous leishmaniasis in southern France.

New treatment options are arising from the new oral drug miltefosine (Impavido) which has shown in several clinical trials to be very efficient and safe in visceral and cutaneous leishmaniasis. Recent studies from Bolivia show a high cure rate for mucocutaneous leishmaniasis. Comparative studies against pentavalent antimonials in Iran and Pakistan are also beginning to show a high cure rate for "L. major" and "L. tropica". It is registered in many countries of Latin America, as well in Germany. In October 2006 it received orphan drug status from the US Food and Drug administration. The drug is generally better tolerated than other drugs. Main side effects are gastrointestinal disturbances in the 1–2 days of treatment which does not affect the efficacy.

Secondary bacterial infection (especially with "Staphylococcus aureus") is common and may require antibiotics. Clinicians who are unfamiliar with cutaneous leishmaniasis may mistake the lesion for a pure bacterial infection (especially after isolation of "S. aureus" from bacterial skin swabs) and fail to consider the possibility of leishmaniasis.

In the United States, certain breed clubs are strongly recommending screening for "Leishmania", especially in imported breeding stock from endemic locations. For reasons yet unidentified The Foxhound and Neapolitan Mastiff seem to be predisposed or at higher risk for disease. The Italian Spinone Club of America is also requesting all breeders and owners to submit samples for testing; the club reported 150 Spinone Italiano dogs have tested positive in the United States.

In the United States, the following veterinary colleges and government bodies assist with testing and treatment of "Leishmania"-positive dogs:

- Centers for Disease Control and Prevention on Leishmaniasis in dogs

- Iowa State University Department of Pathology

- North Carolina State University College of Veterinary Medicine

Diagnostic testing includes molecular biology and genetic techniques which provide high accuracy and high sensitivity/specificity. The most commonly employed methods in medical laboratories include Enzyme-Linked Immunosorbent Assays, aka ELISA (among other serological assays) and DNA amplification via Polymerase Chain Reaction (PCR).

The Polymerase Chain Reaction(PCR) method for detecting "Leishmania" DNA is a highly sensitive and specific test, producing accurate results in a relatively short amount of time.

A study completed in which Foxhounds were tested using PCR showed that approximately 20% of the tested dogs were positive for leishmaniasis; the same population tested with serological/antibody assays showed only 5% positive.

Diagnosis can be complicated by false positives caused by the leptospirosis vaccine and false negatives caused by testing methods lacking sufficient sensitivity.

Leishmaniasis is diagnosed in the hematology laboratory by direct visualization of the amastigotes (Leishman-Donovan bodies). Buffy-coat preparations of peripheral blood or aspirates from marrow, spleen, lymph nodes, or skin lesions should be spread on a slide to make a thin smear and stained with Leishman stain or Giemsa stain (pH 7.2) for 20 minutes. Amastigotes are seen within blood and spleen monocytes or, less commonly, in circulating neutrophils and in aspirated tissue macrophages. They are small, round bodies 2–4 μm in diameter with indistinct cytoplasm, a nucleus, and a small, rod-shaped kinetoplast. Occasionally, amastigotes may be seen lying free between cells. However, the retrieval of tissue samples is often painful for the patient and identification of the infected cells can be difficult. So, other indirect immunological methods of diagnosis are developed, including enzyme-linked immunosorbent assay, antigen-coated dipsticks, and direct agglutination test. Although these tests are readily available, they are not the standard diagnostic tests due to their insufficient sensitivity and specificity.

Several different polymerase chain reaction tests are available for the detection of "Leishmania" DNA. With this assay, a specific and sensitive diagnostic procedure is finally possible.

Most forms of the disease are transmitted only from nonhuman animals, but some can be spread between humans. Infections in humans are caused by about 21 of 30 species that infect mammals; the different species look the same, but they can be differentiated by isoenzyme analysis, DNA sequence analysis, or monoclonal antibodies.

The gold standard for diagnosis is visualization of the amastigotes in splenic aspirate or bone marrow aspirate. This is a technically challenging procedure that is frequently unavailable in areas of the world where visceral leishmaniasis is endemic.

Serological testing is much more frequently used in areas where leishmaniasis is endemic. A 2014 Cochrane review evaluated different rapid diagnostic tests. One of them (the rK39 immunochromatographic test) gave correct, positive results in 92% of the people with visceral leishmaniasis and it gave correct, negative results in 92% of the people who did not have the disease. A second rapid test (called latex agglutination test) gave correct, positive results in 64% of the people with the disease and it gave correct, negative results in 93% of the people without the disease. Other types of tests have not been studied thoroughly enough to ascertain their efficacy.

The K39 dipstick test is easy to perform, and village health workers can be easily trained to use it. The kit may be stored at ambient temperature and no additional equipment needs to be carried to remote areas. The DAT anti-leishmania antigen test, standard within MSF, is much more cumbersome to use and appears not to have any advantages over the K39 test.

There are a number of problems with serological testing: in highly endemic areas, not everyone who becomes infected will actually develop clinical disease or require treatment. Indeed, up to 32% of the healthy population may test positive, but not require treatment. Conversely, because serological tests look for an immune response and not for the organism itself, the test does not become negative after the patient is cured, it cannot be used as a check for cure, or to check for re-infection or relapse. Likewise, patients with abnormal immune systems (e.g., HIV infection) will have false-negative tests.

Other tests being developed include detects erythrosalicylic acid.

In areas where the known vector is a sandfly, deltamethrin collars worn by the dogs has been proven to be 86% effective. The sandfly is most active at dusk and dawn; keeping dogs indoors during those peak times will help minimize exposure.

Unfortunately, there is no one answer for leishmaniasis prevention, nor will one vaccine cover multiple species. "Different virulence factors have been identified for distinct "Leishmania" species, and there are profound differences in the immune mechanisms that mediate susceptibility/resistance to infection and in the pathology associated with disease."

In 2003, Fort Dodge Wyeth released the Leshmune vaccine in Brazil for "L. donovani" (also referred to as "kala-azar" in Brazil). Studies indicated up to 87% protection. Most common side effects from the vaccine have been noted as anorexia and local swelling.

The president of the Brazil Regional Council of Veterinary Medicine, Marcia Villa, warned since vaccinated dogs develop antibodies, they can be difficult to distinguish from asymptomatic, infected dogs.

Studies also indicate the Leshmune vaccine may be reliable in treating "L. chagasi", and a possible treatment for dogs already infected with "L. donovani".

The treatment is determined by where the disease is acquired, the species of "Leishmania", and the type of infection.

For visceral leishmaniasis in India, South America, and the Mediterranean, liposomal amphotericin B is the recommended treatment and is often used as a single dose. Rates of cure with a single dose of amphotericin have been reported as 95%. In India, almost all infections are resistant to pentavalent antimonials. In Africa, a combination of pentavalent antimonials and paromomycin is recommended. These, however, can have significant side effects. Miltefosine, an oral medication, is effective against both visceral and cutaneous leishmaniasis. Side effects are generally mild, though it can cause birth defects if taken within 3 months of getting pregnant. It does not appear to work for "L. major" or "L. braziliensis".

The evidence around the treatment of cutaneous leishmaniasis is poor. A number of topical treatments may be used for cutaneous leishmaniasis. Which treatments are effective depends on the strain, with topical paromomycin effective for "L. major", "L. tropica", "L. mexicana", "L. panamensis", and "L. braziliensis". Pentamidine is effective for "L. guyanensis". Oral fluconazole or itraconazole appears effective in "L. major" and "L. tropica".

There are no vaccines or preventive drugs for visceral leishmaniasis. The most effective method to prevent infection is to protect from sand fly bites. To decrease the risk of being bitten, these precautionary measures are suggested:

- Outdoors:

1. Avoid outdoor activities, especially from dusk to dawn, when sand flies generally are the most active.

2. When outdoors (or in unprotected quarters), minimize the amount of exposed (uncovered) skin to the extent that is tolerable in the climate. Wear long-sleeved shirts, long pants, and socks; and tuck your shirt into your pants.

3. Apply insect repellent to exposed skin and under the ends of sleeves and pant legs. Follow the instructions on the label of the repellent. The most effective repellents generally are those that contain the chemical DEET (N,N-diethylmetatoluamide).

- Indoors:

1. Stay in well-screened or air-conditioned areas.

2. Keep in mind that sand flies are much smaller than mosquitoes and therefore can get through smaller holes.

3. Spray living/sleeping areas with an insecticide to kill insects.

4. If you are not sleeping in a well-screened or air-conditioned area, use a bed net and tuck it under your mattress. If possible, use a bed net that has been soaked in or sprayed with a pyrethroid-containing insecticide. The same treatment can be applied to screens, curtains, sheets, and clothing (clothing should be retreated after five washings)."

On February 2012, the nonprofit Infectious Disease Research Institute launched a clinical trial of the visceral leishmaniasis vaccine. The vaccine is a recombinant form of two fused Leishmania parasite proteins with an adjuvant. Two phase 1 clinical trials with healthy volunteers are to be conducted. The first one takes place in Washington (state) and is followed by a trial in India.

Diagnosis is often made by visualization of yeast cells in tissue, or superficial scrapings. Radiography of the chest reveals interstitial infiltrates in the majority of cases.

The diagnosis is confirmed by a skin biopsy and a positive culture for acid-fast bacilli. A PPD test may also result positive.

Therapy for cutaneous tuberculosis is the same as for systemic tuberculosis, and usually consists of a 4-drug regimen, i.e., isoniazid, rifampin, pyrazinamide, and ethambutol or streptomycin.

Sulfonamides are the traditional remedies to paracoccidiodomycosis. They were introduced by Oliveira Ribeiro and used for more than 50 years with good results. The most-used sulfa drugs in this infection are sulfadimethoxime, sulfadiazine, and co-trimoxazole. This treatment is generally safe, but several adverse effects can appear, the most severe of which are the Stevens-Johnson syndrome and agranulocytosis. Similarly to tuberculosis treatment, it must be continued for up to three years to eradicate the fungus, and relapse and treatment failures are not unusual.

Antifungal drugs such as amphotericin B or itraconazole and ketoconazole are more effective in clearing the infection, but are limited by their cost when compared with sulfonamides.During therapy, fibrosis can appear and surgery may be needed to correct this. Another possible complication is Addisonian crisis. The mortality rate in children is around 7-10%.

Biotechnology companies in the developing world have targeted neglected tropical diseases due to need to improve global health.

Mass drug administration is considered a possible method for eradication, especially for lymphatic filariasis, onchocerciasis, and trachoma, although drug resistance is a potential problem. According to Fenwick, Pfizer donated 70 million doses of drugs in 2011 to eliminate trachoma through the International Trachoma Initiative. Merck has helped The African Programme for the Control of Onchocerciasis (APOC) and Oncho Elimination Programme for the Americas to greatly diminished the effect of Onchocerciasis by donating ivermectin. Merck KGaA pledged to give 200 million tablets of praziquantel over 10 years, the only cure for schistosomiasis. GlaxoSmithKline has donated two billion tablets of medicine for lymphatic filariasis and pledged 400 million deworming tablets per year for five years in 2010. Johnson & Johnson has pledged 200 million deworming tablets per year. Novartis has pledged leprosy treatment, EISAI pledged two billion tablets to help treat lymphatic filariasis.

There are currently only two donor-funded non-governmental organizations that focus exclusively on NTDs: the Schistosomiasis Control Initiative and Deworm the World. Despite under-funding, many neglected diseases are cost-effective to treat and prevent. The cost of treating a child for infection of soil transmitted helminths and schistosomes (some of the main causes of neglected diseases), is less than US$0.50 per year, when administered as part of school-based mass deworming by Deworm the World. This programme is recommended by Giving What We Can and the Copenhagen Consensus Centre as one of the most efficient and cost-effective solutions. The efforts of Schistosomiasis Control Initiative to combat neglected diseases include the use of rapid-impact packages: supplying schools with packages including four or five drugs, and training teachers in how to administer them.

Some of the strategies for controlling tropical diseases include:

- Draining wetlands to reduce populations of insects and other vectors, or introducing natural predators of the vectors.

- The application of insecticides and/or insect repellents) to strategic surfaces such as clothing, skin, buildings, insect habitats, and bed nets.

- The use of a mosquito net over a bed (also known as a "bed net") to reduce nighttime transmission, since certain species of tropical mosquitoes feed mainly at night.

- Use of water wells, and/or water filtration, water filters, or water treatment with water tablets to produce drinking water free of parasites.

- Sanitation to prevent transmission through human waste.

- In situations where vectors (such as mosquitoes) have become more numerous as a result of human activity, a careful investigation can provide clues: for example, open dumps can contain stagnant water that encourage disease vectors to breed. Eliminating these dumps can address the problem. An education campaign can yield significant benefits at low cost.

- Development and use of vaccines to promote disease immunity.

- Pharmacologic pre-exposure prophylaxis (to prevent disease before exposure to the environment and/or vector).

- Pharmacologic post-exposure prophylaxis (to prevent disease after exposure to the environment and/or vector).

- Pharmacologic treatment (to treat disease after infection or infestation).

- Assisting with economic development in endemic regions. For example, by providing microloans to enable investments in more efficient and productive agriculture. This in turn can help subsistence farming to become more profitable, and these profits can be used by local populations for disease prevention and treatment, with the added benefit of reducing the poverty rate.

- Hospital for Tropical Diseases

- Tropical medicine

- Infectious disease

- Neglected diseases

- List of epidemics

- Waterborne diseases

- Globalization and disease

The gold standard for diagnosis is identification of trypanosomes in a patient sample by microscopic examination. Patient samples that can be used for diagnosis include chancre fluid, lymph node aspirates, blood, bone marrow, and, during the neurological stage, cerebrospinal fluid. Detection of trypanosome-specific antibodies can be used for diagnosis, but the sensitivity and specificity of these methods are too variable to be used alone for clinical diagnosis. Further, seroconversion occurs after the onset of clinical symptoms during a "T. b. rhodesiense" infection, so is of limited diagnostic use.

Trypanosomes can be detected from patient samples using two different preparations. A wet preparation can be used to look for the motile trypanosomes. Alternatively, a fixed (dried) smear can be stained using Giemsa's or Field's technique and examined under a microscope. Often, the parasite is in relatively low abundance in the sample, so techniques to concentrate the parasites can be used prior to microscopic examination. For blood samples, these include centrifugation followed by examination of the buffy coat; mini anion-exchange/centrifugation; and the quantitative buffy coat (QBC) technique. For other samples, such as spinal fluid, concentration techniques include centrifugation followed by examination of the sediment.

Three serological tests are also available for detection of the parasite: the micro-CATT, wb-CATT, and wb-LATEX. The first uses dried blood, while the other two use whole blood samples. A 2002 study found the wb-CATT to be the most efficient for diagnosis, while the wb-LATEX is a better exam for situations where greater sensitivity is required.

A canine vector-borne disease (CVBD) is one of "a group of globally distributed and rapidly spreading illnesses that are caused by a range of pathogens transmitted by arthropods including ticks, fleas, mosquitoes and phlebotomine sandflies." CVBDs are important in the fields of veterinary medicine, animal welfare, and public health. Some CVBDs are of zoonotic concern.

Many CVBD infect humans as well as companion animals. Some CVBD are fatal; most can only be controlled, not cured. Therefore, infection should be avoided by preventing arthropod vectors from feeding on the blood of their preferred hosts. While it is well known that arthropods transmit bacteria and protozoa during blood feeds, viruses are also becoming recognized as another group of transmitted pathogens of both animals and humans.

Some "canine vector-borne pathogens of major zoonotic concern" are distributed worldwide, while others are localized by continent. Listed by vector, some such pathogens and their associated diseases are the following:

- Phlebotomine sandflies (Psychodidae): "Leishmania amazonensis", "L. colombiensis", and "L. infantum" cause visceral leishmaniasis (see also canine leishmaniasis). "L. braziliensis" causes mucocutaneous leishmaniasis. "L. tropica" causes cutaneous leishmaniasis. "L. peruviana" and "L. major" cause localized cutaneous leishmaniasis.

- Triatomine bugs (Reduviidae): "Trypanosoma cruzi" causes trypanosomiasis (Chagas disease).

- Ticks (Ixodidae): "Babesia canis" subspecies ("Babesia canis canis", "B. canis vogeli", "B. canis rossi", and "B. canis gibsoni" cause babesiosis. "Ehrlichia canis" and "E. chaffeensis" cause monocytic ehrlichiosis. "Anaplasma phagocytophilum" causes granulocytic anaplasmosis. "Borrelia burgdorferi" causes Lyme disease. "Rickettsia rickettsii" causes Rocky Mountain spotted fever. "Rickettsia conorii" causes Mediterranean spotted fever.

- Mosquitoes (Culicidae): "Dirofilaria immitis" and "D. repens" cause dirofilariasis.

Currently there are few medically related prevention options for African Trypanosomiasis (i.e. no vaccine exists for immunity). Although the risk of infection from a tsetse fly bite is minor (estimated at less than 0.1%), the use of insect repellants, wearing long-sleeved clothing, avoiding tsetse-dense areas, implementing bush clearance methods and wild game culling are the best options to avoid infection available for local residents of affected areas.

At the 25th ISCTRC (International Scientific Council for Trypanosomiasis Research and Control) in Mombasa, Kenya, in October 1999, the idea of an African-wide initiative to control tsetse and trypanosomiasis populations was discussed. During the 36th summit of the Organization for African Unity in Lome, Togo, in July 2000, a resolution was passed to form the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC). The campaign works to eradicate the tsetse vector population levels and subsequently the protozoan disease, by use of insecticide-impregnated targets, fly traps, insecticide-treated cattle, ultra-low dose aerial/ground spraying (SAT) of tsetse resting sites and the sterile insect technique (SIT). The use of SIT in Zanzibar proved effective in eliminating the entire population of tsetse flies but was expensive and is relatively impractical to use in many of the endemic countries afflicted with African trypanosomiasis.

Regular active surveillance, involving detection and prompt treatment of new infections, and tsetse fly control is the backbone of the strategy used to control sleeping sickness. Systematic screening of at-risk communities is the best approach, because case-by-case screening is not practical in endemic regions. Systematic screening may be in the form of mobile clinics or fixed screening centres where teams travel daily to areas of high infection rates. Such screening efforts are important because early symptoms are not evident or serious enough to warrant patients with gambiense disease to seek medical attention, particularly in very remote areas. Also, diagnosis of the disease is difficult and health workers may not associate such general symptoms with trypanosomiasis. Systematic screening allows early-stage disease to be detected and treated before the disease progresses, and removes the potential human reservoir. A single case of sexual transmission of West African sleeping sickness has been reported.

As of tissue or discharge are generally unreliable, the diagnosis of mucormycosis tends to be established with a biopsy specimen of the involved tissue.

Post-kala-azar dermal leishmaniasis (also known as "Post-kala-azar dermatosis") is a cutaneous condition that is characterized by depigmented macular, maculopapular and nodular eruptions found mainly on the face, arms, and upper part of the trunk. It occurs years(in the Indian variation)or a few months(in the African strain) after the successful treatment of visceral leishmaniasis

Cutaneous amoebiasis refers to a form of amoebiasis that presents primarily in the skin.

It can be caused by "Acanthamoeba" or "Entamoeba histolytica". When associated with "Acanthamoeba", it is also known as "cutaneous acanthamoebiasis".

It is also known as "amoebiasis cutis".

"Balamuthia mandrillaris" can cause cutaneous amoebiasis, but can prove fatal if the amoeba enters the bloodstream

Tropical diseases are diseases that are prevalent in or unique to tropical and subtropical regions. The diseases are less prevalent in temperate climates, due in part to the occurrence of a cold season, which controls the insect population by forcing hibernation. However, many were present in northern Europe and northern America in the 17th and 18th centuries before modern understanding of disease causation. The initial impetus for tropical medicine was to protect the health of colonialists, notably in India under the British Raj. Insects such as mosquitoes and flies are by far the most common disease carrier, or vector. These insects may carry a parasite, bacterium or virus that is infectious to humans and animals. Most often disease is transmitted by an insect "bite", which causes transmission of the infectious agent through subcutaneous blood exchange. Vaccines are not available for most of the diseases listed here, and many do not have cures.

Human exploration of tropical rainforests, deforestation, rising immigration and increased international air travel and other tourism to tropical regions has led to an increased incidence of such diseases.

Painful red swelling of the hands and feet in a patient receiving chemotherapy is usually enough to make the diagnosis. The problem can also arise in patients after bone marrow transplants, as the clinical and histologic features of PPE can be similar to cutaneous manifestations of acute (first 3 weeks) graft-versus-host disease. It is important to differentiate PPE, which is benign, from the more dangerous graft-versus-host disease. As time progresses, patients with graft-versus-host disease progress to have other body parts affected, while PPE is limited to hands and feet. Serial biopsies every 3 to 5 days can also be helpful in differentiating the two disorders (Crider et al., 1986).

The diagnostic testing for vasculitis should be guided by the patient's history and physical exam. The clinician should ask about the duration, onset, and presence any associated symptoms such as weight loss or fatigue (that would indicate a systemic cause). It is important to distinguish between IgA and non-IgA vasculitis. IgA vasculitis is more likely to present with abdominal pain, bloody urine, and joint pain. In the case that the cause is not obvious, a reasonable initial workup would include a complete blood count, urinalysis, basic metabolic panel, fecal occult blood testing, erythrocyte sedimentation rate (ESR), and C-reactive protein level. Small vessel cutaneous vasculitis is a diagnosis of exclusion and requires ruling out systemic causes of the skin findings. Skin biopsy (punch or excisional) is the most definitive diagnostic test and should be performed with 48 hours of appearance of the vasculitis. A skin biopsy will be able to determine if the clinical findings are truly due to a vasculitis or due to some other cause.

If mucormycosis is suspected, amphotericin B therapy should be immediately administered due to the rapid spread and high mortality rate of the disease. Amphotericin B is usually administered for an additional 4–6 weeks after initial therapy begins to ensure eradication of the infection. Isavuconazole was recently FDA approved to treat invasive aspergillosis and invasive mucormycosis.

After administration of either amphotericin B or posaconazole, surgical removal of the "fungus ball" is indicated. The disease must be monitored carefully for any signs of reemergence.

Surgical therapy can be very drastic, and in some cases of disease involving the nasal cavity and the brain, removal of infected brain tissue may be required. In some cases surgery may be disfiguring because it may involve removal of the palate, nasal cavity, or eye structures. Surgery may be extended to more than one operation. It has been hypothesized that hyperbaric oxygen may be beneficial as an adjunctive therapy because higher oxygen pressure increases the ability of neutrophils to kill the organism.