Monday, October 22, 2018

Case of the Week 516

This week's case was generously donated by Dr. Josette McMichael, an American dermatologist currently working in east Africa. The patient is an elderly woman who presented with a 2-week history of 10 pruritic burning nodules involving her left upper arm, face, breast, chest, trunk, and legs. Here is a video of one of the lesions:

This object was removed and placed in a sterile container without preservative:
It was still quite lively!

Approximately 1 week later, it was sent to my lab for identification. Even though it had darkened significantly, the diagnostic features were still apparent. Here is the posterior end:


Anonymous said...

Entomology has always been my Achilles's tendon. The lessons gathered over the years from the Blog give me the following remarks:
1. The patient is from Africa, where we can find the tumbu fly.
2. The size of the larva is about one third or one fourth the diameter of the cup, roughly 13-15 mm in length, compatible to that of this fly's larva size.
3. There is no discernible peritreme nor ecdysial scar.
4. The spiracles open through sinuous slits.
5. "All things considered", this lead me to a diagnosis of myasis caused by Cordylobia anthropophaga.
Florida Fan

Sam said...

Myiasis caused by the larva of botfly species Cordylobia anthropophaga.

Larry Ritchie said...
This comment has been removed by a blog administrator.
Old One said...

Three bot-like dipterans come to mind. The 'Congo floor maggot', Auchmeromyia. This genus was rejected because it doesn't form Furuncles (boil-like lesions with a live dipteran maggot within), but rather feeds bedbug style. Staying on the host only for feeding. It's spiracular slits are 3 per side, straight, laying horizontally.

There are several species of mucoid flies(not bots) in the genus Cordylobia that cause a furuncular cutaneous myiasis as described by the good Dr.

The Tumba fly, C. arthropophaga and Lunds fly C.rodhani both have 3 posterior spiracular slits on each side, and are curved. This is constant with specimen in question. Both species are found in East Africa. Although C. arthropophaga is most commonly encountered, I cannot distinguish the two species. I must limit my Identification to Cordylobia sp.

Blaine A. Mathison said...

This is Cordylobia anthropophaga. The slits on the spiracular plate of C. rodhaini are much more sinuous.

Old One said...

I looked up some images on Google. I see what you mean. Thanks Blaine

Anonymous said...

Thank you Old Man for bringing up the subject. Thank you Blaine for the answer. I found the picture of the spiracles of C. rodhaini too. You all gave me more knowledge.
Florida Fan

William Sears said...

Tumbu, cordylobia