Sunday, February 19, 2017

Case of the Week 435

This week's challenging case was donated by Dr. Emily Hall. The patient is a previously-healthy toddler who began acting unusually fussy and refused to ambulate. Examination reviewed a thin black object under the skin of her right foot. Extraction was unsuccessful and the child was playing and ambulating at the end of the visit and was therefore sent home. The child was brought back the following day because the object had moved approximately 3 cm within a 24 hour period in the semilunar pattern shown in the image below:
At this point, the object was removed and sent to the parasitology lab. Rather than showing you the images of the object that was extracted, I thought I would ask for your diagnosis based on the clinical image alone. I will show you the images and provide the diagnosis next week!

The image is shown with permission from the mother.

14 comments:

merrymayo said...

Larva migrans?

Sugar Magnolia said...

merrymayo - that's exactly what I was thinking. Cutaneous larva migrans caused by Necator americanus (hookworm). Interesting case I'm not ever likely to see in practice.

Zachary Telfer said...

Initially I jumped to Cutaneous larva migrans (CLM). However, the picture is not exactly how CLM would present. This is a picture of a seemingly thin superficial black object that is moving in a relatively strait trajectory, whereas CLM moves in a very serpiginous fashion with a lot of inflammation. Other cutaneous worms in the differential were Loiasis or Onchocerciasis, but they didn’t fit the clinical picture. After some searching, my guess is Cutaneous pili migrans (CPL). Not a parasite at all, CPL may be a foreign hair shaft that is migrating through the foot by the pressure exerted on it by walking.

Anonymous said...

The presentation of the case favors a transcutaneous implantation, and as such would lead us to a hook worm as causative agent.
Florida Fan

Anonymous said...

I don't think is a Larva migrans...
We are on a roll of pediatric cases! So nice.

-HLCM fan.

Anonymous said...

Well, we are having a healthy and lively discussion. The dark color of the object and its size are not compatible with the clinically significant nematodes even microfilarias or animal nematodes. The other fact is that there is a lack of tissue reaction in this case, so a diagnosis of larva migrans may not be supported.
The enigma awaits a week long, before the enlightenment arrives.
Florida Fan

Andrea Zambrano said...

Lack of inflamation surrounding the lesion and it looks like there may be a port of entry on the sole of the foot favoring foreign body.

mona said...

larva currens (strongyloides stercoralis larva in skin)
or
cutaneous larva migrans (ankylostoma caninum )?

Arthur V said...

Well the differential would be nematodes that migrate through the subcutaneous layers of the skin, which would include hookworms (ancylostoma spp., necator spp., and even zoonotic hookworms which may cause CLM but not establish, such as Bunostomum), filariae such a loa loa, Larva currans from Strongyloides etc. However, I would expect to see more inflammation and a more serpiginous inflammation track from each of these. Also, the body appears to be of about 1.5-2cm in length and black, which is inconsistent with any of these cutaneous migratory nematodes. This leads me to conclude that this is a foreign body of non-parasitic origin, and is likely to be Cutaneous Pili Migrans: a migrating hair.
This actually took me on a tour of google to find out what non-parasitic body may have been the causative agent, fascinating case!

Arthur

Kenji said...

I suspect strongyloides stercoralis larva migrating in the skin

Anonymous said...

I want to add that pictures of diptera myiasis often show a black or thread like object near the larva. I'm not sure which diptera would be causing this cutaneous or migratory myiasis, but I have read that hypoderma may be one of the most likely, if in fact it is a diptera myiasis.

Unknown said...
This comment has been removed by the author.
Anonymous said...

Anxious to see the answer

Dr. Bhushan said...

Cutaneous pili migrans