Is It Really A Boil?

Boils-inflamed, painful, pus-filled bumps-which often result from an infection on the surface of the skin, can often easily be identified and treated. However, in some circumstances, what appears to be a boil is really something quite different and requires the attention of a medical professional to effect healing.

Myia Is Greek For Fly

A condition known as myiasis can present as a boil, abscess, cellulitis, or furunculosis (folliculitis), among other things. Myiasis is the infestation of the skin by growing larvae of one of a variety of different flies. Myia is the Greek word for fly. Two common flies worldwide that cause human infestations are the human botfly and the tumbu fly, both found in tropic and sub-tropic climates. While still relatively uncommon in the US, the incidence rates are increasing among individuals who travel to tropical destinations or spend a lot of time in outdoor activities. A study in both urban and suburban US found a link between homelessness, alcoholism, and peripheral vascular disease with the two main clinical types of myiasis-wound myiasis and follicular myiasis.

It Looks Like A Boil, Hurts Like A Boil, But...

When a person is infested with the eggs of the fly, a boil-like lesion appears, usually on exposed areas of the body like the scalp, face, arms and legs-all of the places common boils might appear. Furuncular (follicular) myiasis, caused by both the human botfly and the tumbu fly, can occur on the trunk, thigh and buttocks as well as other exposed areas. The fly eggs are deposited and within 24 hours of penetration, the papule develops, growing to 1-3cm in diameter and almost 1 cm in height. The lesions formed by these growing larvae can be very painful and tender.

In wound myiasis, the larvae are deposited in an open wound and since the larvae are actually visible, there is no boil-like lump, unless they have burrowed beneath the injury. There are also several other physical manifestations of myiasis which do not produce a boil-like lump. These infestations present in a wide variety of ways and can be difficult to diagnose immediately.

Use Of Scan And Types Of Treatment For Infestations

MRI or ultrasound can establish a diagnosis and determine the size of the larvae. CT scan and Doppler ultrasonography (DUSG) are effective to assess the size and situation within a lesion. When the lesions are still very small and not painful, the use of DUSG has proven to be very successful in diagnosing infestations.

The most preferred method of treating an infestation is by surgical removal using a local anesthetic. The lesion is then cut off and closed with stitches. The doctor may inject lidocaine forcibly into the base of the lesion in a bid to force the larvae out of the top of the "boil." It is imperative that great care be used in the removal of the larvae to ensure nothing is left behind. Antiseptic dressing and antibiotics are usually given afterward.

There are several other treatments for myiasis, but the surgical method seems to be the most effective.