What does fungus negative mean

In life, there are many pathogens that cause infections, including bacterial infections and fungal infections. Patients with fungal infections generally show fungal negativity. Fungal negativity is caused by the infection of the skin. There are many types of fungi, and you need to know the type of fungal infection in order to treat the disease. Let us now understand what fungus negative means.

A negative fungal test result means that no fungal infection was found in the sample examined. It is also possible that fungi are present in the sample examined, but no fungi, nor fungal spores or hyphae are found in the sample sent for testing. In this case, the test result may be negative. There are two possible situations. One is truly negative, and the second is a false negative. False-negative fungi are not easy to detect, the detection rate is very low, and repeated tests may be required. If the disease is not detected the first time, clinically it is still considered to be a fungal infection and another fungal examination may be necessary. Including fungal examination of blood or sputum, only through repeated examinations can a correct conclusion be drawn. The above content is for reference only. Please follow the doctor's face-to-face consultation instructions for specific medication and treatment.

Tests for fungal skin infections:

1. Fungal microscopic examination: Select a few scales or hairs at the edge of the lesions. Place on a glass slide, add a drop of potassium hydroxide solution, and cover with a glass slide. Then heat it on an alcohol lamp for a few moments to promote the dissolution of keratin. Finally, microscopic observation was performed. A positive fungal test confirms the diagnosis, but a negative result cannot rule out the diagnosis of ringworm.

2. Fungal culture: The conventional culture medium is Sabourauad medium. After inoculation, the scales, hair or blister membrane taken from the lesion are placed in a constant temperature box at 25~30℃ for culture. Generally, colony growth can be seen in about 5 days, and then the strain can be identified. If no colonies grow after three weeks of culture, the culture can be reported as negative.

3. Check with filtered ultraviolet lamp: This lamp, also known as Wood's lamp, is a device in which ultraviolet rays pass through a glass containing nickel oxide. In a dark room, certain fungi can be seen producing colored fluorescence under the irradiation of filtered ultraviolet lamp. This can provide important reference for the clinical diagnosis of superficial fungal diseases, especially tinea capitis, based on the presence or absence and color of fluorescence. In addition, the light is also helpful for group inspections in nurseries, for example.