The pathogenesis of the chronic salivary inflammatory disease spectrum also has changed with the interplay between sialadenitis, sialectasis, and sialolithiasis. A heterogeneous group of disorders in chronic inflammatory sialadenitis also exist, which include the group of specific and nonspecific granulomatous diseases.
Juvenile Recurrent Parotitis (JRP)
Juvenile recurrent parotitis (JRP), which was formally known as recurrent parotitis of childhood, is the most common inflammatory salivary gland disorder in children in the United States and is second only to mumps worldwide. This condition presents with recurrent inflammation and infection without a definitive etiology. The onset is generally between 3 and 6 years of age, and recurrent episodes continue throughout puberty, when the disease usually resolves. Patients present with pain and edema over the involved gland (often the parotid) and can have systemic symptoms such as fever. On physical exam, patients often have enlarged Stensen’s papilla with associated yellowish plaques of protein coagulum around the opening. Treatment is medical, but sialadenoscopic washout and irrigation has also been described with success (10
Both flexible and rigid sialadenoscopy have been used for both diagnostic and therapeutic treatment of salivary gland disorders. Small rigid scopes with working ports for saline, antibiotic, or steroid irrigation as well as for balloon dilation are available. One study of 36 patients with JRP showed a 92% recurrence-free rate at 36 months after sialadenoscopic irrigation and steroid infusion (11
). Another study of six children had 100% success rate in treating recurrent infections (12
). Further research is necessary to further delineate the role of this treatment modality in pediatric salivary gland disease.
Chronic inflammation of the salivary glands can lead to ductal dilation, chronic salivary stasis, ascending infections, and parenchymal destruction. It is seen mostly in the adult with a history of childhood recurrent sialadenitis, sialolithiasis, and strictures. The presentation is unilateral, diffuse enlargement of the involved gland with swelling related to eating. Sialography can identify a stricture with proximal ductal dilation. The management includes a spectrum of therapies including ductal dilation or duct incision (if the stricture is distal). Conservative therapy is less effective in management of parotid sialectasis. In this situation, a parotidectomy with facial nerve preservation is required.
Because of the morbidity associated with facial nerve dissection in an inflamed field, alternative modes of therapy have been proposed. The use of botulinum toxin A to modulate parasympathetic stimulation and reduce salivary flow has been reported (13
). The theory is that chemical denervation leads to atrophy of parotid gland acini.
Relative to adults, sialolithiasis is a rare condition in the pediatric population. Relatively few cases of pediatric calculus formation in the salivary glands have been reported in the literature. In a review done in 1995, in total, 86 cases were cited. The submandibular glands are the most common site for calculus formation, followed in frequency by the parotid gland. The sublingual glands and the minor salivary glands are rarely affected. Physiologic factors such as alkaline pH, high calcium concentration, and mucin content of the saliva contribute to stone formation. Furthermore, it has been speculated that the tortuosity of Wharton duct with passage of secretions against gravity can promote stasis and calculi (14
). The most common presenting symptoms include intermittent, unilateral swelling in the affected gland with ipsilateral pain, all associated with eating.
When an obstruction is suspected, radiography is 90% sensitive. In the past, panoramic and anteroposterior films were used; however, because of bony overlap of the facial
skeleton, these studies are not effective at identifying calculi. Axial CT scans are useful in identifying radiopaque sialoliths. The majority of stones can be found along the course of the ducts (Stensen’s or Wharton duct) (14
) with a rare occurrence of intraparenchymal stones. Most submandibular gland calculi are radiopaque, while a significant majority of parotid stones are radiolucent. Nonopaque sialoliths can be identified with ultrasonography and, in particular, color Doppler ultrasonography (15
The underlying pathophysiology leading to stone formation is stasis secondary to either duct obstruction, decreased saliva production, or a side effect of pharmacotherapy. The most common etiology of chronic duct obstruction is mucous plugging with deposition of calcium salts. Accidental biting of Stensen’s duct also can contribute to duct stricture and stasis. Decreased salivary production due to autoimmune disease is less commonly encountered in the pediatric population.
The aim of management of sialolithiasis is to restore the normal parenchymal architecture of the gland and allow its long-term functional recovery. A conservative and mostly effective mode of therapy includes stimulation of saliva production by instructing the child to suck on acidic sialogogues. In children, submandibular stones have been reported to pass out of the duct spontaneously after this maneuver. Spontaneous passage of parotid stones is less likely because of the pathway of Stensen’s duct through the buccinator muscle (15
If conservative treatment fails, alternative modes of therapy include duct dilation, sialolithotomy, or sialadenectomy. The latter is indicated if the stone is located in the posterior third of the gland or when damage to the parenchyma of the gland results in a nonfunctional gland. To evaluate this, radiographic imaging including sialography, scintigraphy, ultrasonography, and MRI can be used.
Because of the potential morbidity associated with sialolithotomy and sialadenectomy, a less invasive mode of therapy has been recently proposed. Extracorporeal electromagnetic shockwave lithotripsy (EESWL) has improved the nonsurgical approach to treatment of salivary gland calculi (15
). In their report of seven patients treated with noninvasive EESWL, Ottaviani and colleagues reported complete stone disintegration in 71% of the patients and 29% partial resolution. EESWL therapy is instituted after resolution of the acute inflammatory state with antibiotics and antiinflammatory agents. Symptom relief was observed in all patients who were studied. After an average of five sessions, all but one had complete functional recovery of the gland, as observed on scintigraphy (15
). McJunkin et al. (16
) recently described a case of treatment of a 2-cm parotid sialolith with a single session of lithotripsy with complete resolution.