Overview
Lung mite disease is a pulmonary parasitic disease caused by lung-loving mites that invade the organism with air, water and food, pass through the respiratory tract and parasitize the lungs. It is a slow onset disease with variable clinical manifestations, either resembling a cold, bronchitis, tuberculosis, or asthma-like attacks. The vast majority of patients have cough and sputum, followed by anorexia and malaise, low-grade fever, chest tightness, chest pain, night sweats, shortness of breath or asthma. If the mites also invade the skin or the digestive tract, itching, rash or abdominal pain, diarrhea, weight loss may occur.
Causes
It is a pulmonary parasitic disease caused by lung-loving mites that invade the organism with air, water and food, pass through the respiratory tract and parasitize the lungs. This disease has obvious occupational, engaged in grain and herbal medicine storage, processing, sales and textile workers prevalence is significantly higher than the general population.
Symptoms
Slow onset, variable clinical manifestations, or similar to colds, bronchitis, or similar to tuberculosis, or asthma-like attacks. The vast majority of patients have cough and sputum, followed by anorexia, malaise, low-grade fever, chest tightness, chest pain, night sweats, shortness of breath or asthma. Sputum is mostly white foamy, occasionally with blood in the sputum, and purulent sputum when combined with bacterial infection. Some patients have prolonged dry cough, or severe asthma. On examination, dry rales can be heard in the lungs, and a few have wet rales or rales. If the mite also invades the skin or digestive tract, itching, rash or abdominal pain, diarrhea, weight loss may occur.
Examination
1. General examination
Peripheral blood leukocytes are normal or mildly increased. Eosinophils are often increased, accounting for 10% to 50%. Serum IgE is obviously increased, which can be 5-6 times of normal, IgG and IgA are also increased, and IgM is increased to different degrees in the early stage of the disease, but there is no significant difference compared with the control group. Sputum may have more eosinophils. Occasionally, Charcot crystals are seen. Leave 24h sputum digested by 5%-7.5% sodium hydroxide for 2-3h, and centrifugal smear microscopic examination to find adult mites, larvae or eggs can confirm the diagnosis.
2.Immunological examination
Commonly used: ① skin test Mostly used mite allergen prick test (SPT), the total positive rate of 80%. ② indirect fluorescent antibody test (IFA) method is simple, sensitivity and specificity are good, the positive rate is more than 90%. Indirect hemagglutination test (IHA) The positive rate is slightly lower than that of IFA, about 85%, and its specificity is also better, and its titer should be ≥1:16 for the diagnosis of lung mite disease. ④ Biotinin-affinity enzyme-linked immunosorbent assay (ABC-ELISA) The method is simple, fast and easy to promote, and its positive rate is about 80%. ⑤ Enzyme-linked immunosorbent assay (EIISA) A method of serum antibody detection for mite patients. If the absorbance value OD≥3 is taken as positive, the positive compliance rate for patients with pulmonary mite disease is 83%, the negative compliance rate for patients with respiratory diseases other than pulmonary mite disease is 90%, and the negative compliance rate for healthy people is 95%. Because it has the advantages of high sensitivity and high specificity, it can be used for the diagnosis of pulmonary mite disease and the epidemiological investigation of key populations. However, these tests must be combined with clinical examination for correct diagnosis.
3.Imaging examination
The main signs of X-ray manifestations include widening of the shadow of the lung portal, thickening and disorganization of the texture, cloudy shadows in the middle and lower fields of the two lungs, and scattered nodular or speckled shadows of varying sizes (2-5mm) in the portal area of the lungs and the two lungs, which are the characteristic X-ray manifestations of pulmonary mite disease.
Diagnosis
Engaged in grain, herbal medicine or textile storage, processing, transfer, sales and close contacts, such as with respiratory symptoms or signs, after long-term anti-infective treatment does not improve or sometimes light and sometimes heavy, prolonged, blood eosinophilia, X-ray lung portal widening, coarse texture, there are scattered nodules or small patchy shadows; immunological examination of serum mite-specific antibody is positive, it should be suspected, such as sputum to find mite adult worms, If sputum find mite adult, larvae or eggs, the diagnosis can be confirmed.
Treatment
Metronidazole has good efficacy in killing mites, easy to take, few adverse reactions, and the efficacy can be more than 90%. If there is no significant improvement after 3 courses of treatment, other drugs such as praziquantel should be used. If combined with lung infection, targeted antibiotic treatment, adverse reaction symptoms can be added with metoclopramide and other symptomatic treatment.