This condition arises due to a fracture of more than one bony orbital walls of paranasal sinuses and tearing of adjacent sinus mucosa, and communication of a sinus with the orbit is established. This fracture usually involves the ethmoid, and sometimes involves frontal, sphenoid, and maxillary sinuses. The air usually enters the orbit when the pressure within the upper respiratory tract is increased due to expiratory efforts, nose blowing or sneezing. Orbitopalperbal emphysema
Orbitopalpebral emphysema refers to the trapping of air inside both the soft tissues of the orbit and the eyelid. It is usually a sequelae of a true orbital emphysema. When too much air accumulates inside the orbit, the orbital septum ruptures due to high intraorbital pressure. Air may then pass freely from the orbit into the eyelids through the break in the orbital septum. Stages
There are four stages of orbital emphysema. Stage I
Stage I orbital emphysema can only be diagnosed with radiological films. There is only a small amount of intraorbital air, and the patient does not show any clinical signs or symptoms. Stage II
Stage II orbital emphysema develops as the intraorbital air volume increases, causing the eyeball to displace horizontally or vertically (globe dystopia) or to protrude anteriorly (proptosis). The patient may experience diplopia as a result of the globe displacement. Stage III
Stage III orbital emphysema develops when the limits of spontaneous decompression are exceeded.
In vitro, the drug produces vacuolization and disruption of the tegument in the neck of the worms, but not in more posterior portions of the strobila. Praziquantel is well absorbed when taken orally, and it undergoes first-pass metabolism and 80% of the dose is excreted as metabolites in urine within 24 hours. Repeated treatment is required for H. nana at an interval of 7–10 days.Praziquantel as a single dose (25 mg/kg) is the current treatment of choice for hymenolepiasis and has an efficacy of 96%. Single-dose albendazole (400 mg) is also very efficacious (>95%).A three-day course of nitazoxanide is 75–93% efficacious. The dose is 1 g daily for adults and children over 12; 400 mg daily for children aged 4 to 11 years; and 200 mg daily for children aged 3 years or younger. Prognosis
Cure rates are extremely good with modern treatments, but successful cure results may be of no symptomatic benefit to patients. See also
List of parasites (human)

References
Further reading
MedlinePlus Encyclopedia: Hymenolepiasis
"Hymenolepiasis". CDC - DPDx. 2013-11-29. Retrieved 2015-11-01. == External links ==