Mumps is actually a systemic infection, and the virus often involves the central nervous system or other glands or organs to produce the appropriate symptoms. Even some complications are not only common but may occur independently of parotid enlargement.
1. Neurological complications:
(1) Aseptic meningitis, meningoencephalitis, encephalitis.
For common complications. Symptoms of meningoencephalitis can appear as early as 6 days before or 2 weeks after parotid swelling, and generally more often within 1 week after swelling. Cerebrospinal fluid and symptoms are similar to those of other viral encephalitis, with headache, vomiting and other acute cerebral edema manifestations being more pronounced. The EEG may be altered but is not as pronounced as in other viral encephalitis, with meningeal involvement predominating. The prognosis is mostly good, but individual cases of encephalitis may also lead to death.
(2) Polyneuritis, poliomyelitis, etc.
Occasionally, polyneuritis and poliomyelitis appear 1-3 weeks after mumps, and the prognosis is mostly good. The enlarged parotid gland may compress the facial nerve causing temporary facial nerve palsy. Sometimes balance disorders, trigeminal neuritis, hemiplegia, paraplegia, and ascending paralysis occur. Occasionally, hydrocephalus may be complicated by narrowing of the conduit after parotiditis.
(3) Deafness.
It is caused by the involvement of the auditory nerve. Although the incidence is not high (about 1/15,000), it can become permanent and complete deafness, but fortunately, 75% of them are unilateral, so the effect is less.
2. Reproductive complications.
The mumps virus is good at invading the mature genital glands, so it is mostly seen in patients after late adolescence and is rare in pediatric patients.
(1) Testicular infection.
The incidence is 14%-35% of male adult patients. It often occurs when the swelling of the parotid gland begins to subside in about 1 week, with sudden onset of high fever, chills, testicular swelling and pain with severe tenderness, with varying severity of symptoms, and generally subsiding in about 10 days. Scrotal skin edema is also prominent, and yellow fluid may accumulate in the sheath cavity. Most of the lesions invade one side, and testicular atrophy occurs to varying degrees in about 1/3-1/2 of cases. Since the lesions are often unilateral, even if bilateral, only part of the varicocele is involved, it rarely leads to infertility.
(2) Ovarian inflammation.
It accounts for about 5-7% of adult female patients. The symptoms are mild and do not affect conception, and occasionally may cause early amenorrhea. The symptoms of ovarian inflammation include lower back pain, light pressure pain in the lower abdomen, menstrual cycle disorders, and in severe cases, enlarged ovaries with pressure pain can be found.
3. Pancreatitis.
It is seen in about 5% of adult patients and is rare in children. It usually occurs 3-4 days to 1 week after the swelling of the parotid gland, with severe pain and tenderness in the upper and middle abdomen as the main symptoms. It is accompanied by vomiting, fever, abdominal distension, diarrhea or constipation, etc. Sometimes an enlarged pancreas can be found. The symptoms of pancreatitis mostly disappear within 1 week. Blood amylase should not be used as a basis for diagnosis. Lipase is usually elevated 72 h after the onset of the disease, so the early diagnosis is of little value. Complications of pancreatitis have increased in recent years as pediatric patients have become sicker and sicker.
4, nephritis.
Mumps virus can be isolated in the urine of the majority of early cases, so it is believed that the virus can directly damage the kidneys, a small amount of protein in the urine of mild cases, the urinary routine and clinical manifestations of severe cases similar to nephritis, individual severe cases can occur in acute renal failure and death. But most have a good prognosis.
5. Myocarditis.
About 4-5% of patients are complicated by myocarditis. Most often seen on day 5 to day 10 of the disease, can occur at the same time as the parotid swelling or during the recovery period. The symptoms are pallor, increased or decreased heart rate, low heart sound, arrhythmia, temporary heart enlargement, and systolic murmur. The ECG shows sinus arrest, atrioventricular block, ST-segment depression, T-wave depression or inversion, and preterm contraction. Severe cases can be fatal. Most only have ECG changes (3-115%) without obvious clinical symptoms, occasionally with pericarditis.
6. Other.
Mastitis (31% of female patients over 15 years of age are complicated by this disease), osteomyelitis, hepatitis, pneumonia, prostatitis, vestibular adenitis, thyroiditis, thrombocytopenia, urticaria, acute follicular conjunctivitis, etc. are rare. The incidence of arthritis is about 0.44%, mainly involving large joints such as elbow and knee, which can last from 2 days to 3 months and can recover completely. It mostly occurs within 1-2 weeks after parotid swelling, but there are also cases without parotid swelling.