Solving the Mystery Rash in Schools
October of 2001 through April of 2002, schools in the United States
and Canada reported outbreaks of a mysterious,
superficial, skin rash sometimes accompanied by eye inflammation/
swelling (conjunctivitis), and naso-sinus congestion. Itchy
pin-prick dots to papular-macular lesions appeared most often
on the face, neck, arms and hands, but erupted on
covered areas too. The children also had skin inflammation without
lesions that appeared and disappeared very quickly. The condition
didn't produce fever or systemic signs.
The problem appeared to be infectious, but not contagious. Children
who were symptomatic at school cleared up at home, and did
not infect family members. Upon return to school, some became
symptomatic again. Contact with paper, books, instructional materials,
backpacks, coats, furniture and carpet was implicated in
the outbreaks. Investigators who removed ceiling tiles and did
structural checks developed rashes themselves.
Epidemiological teams have eliminated known infective agents and
pollutants/contaminants from consideration, and have ruled out blood
feeding arthropods. Some spokespersons announced they may
never solve the cases.
The epidemic offers several clues to what it is. The
agent survives unnoticed in the human environment. where it infests a
wide range of organic materials. A probably misidentified fallout of
"dandruff," "skin particles," "sparkly dust," and "itching
powder" is reported. The organism
attacks during the day and produces a
non-contagious, skin-orifice infection. It presents a
fast-fading skin sign as well as a rash. Acute symptoms are
self-limiting and last approximately 16 days barring reinfection..
Although it doesn't often come to mind, a parasitic infection can be
very much like the better known ones in appearance and location.
For example, skin parasitism easily produces eczema, papular lesions,
swelling, and itching dermatitis. A parasitic conjunctivitis may look
no different than a viral or allergic conjunctivitis. Therefore, a
parasite may be the answer.
A very successful parasite is unsuspected, doesn't kill the host,
and overrides the immune response so that its presence is masked.
The mystery perpetrator just misses accomplishing all this. Most
likely, it is a non-biting, minor filth fly that is parasitic
during its life cycle.
Infected staff and students may have suffered what is known as
a cutaneous, ocular, naso-sinus myiasis probably caused by
the domestic phorid Megaselia scalaris. Its larvae are
known to be predatory, parasitoid or parasitic depending on the size of
the host, but it has never been thought medically
important. Phorid infections involving the skin and the body
openings are in the literature as medical curiosities.
Investigators would not have considered phorid samples worthy
of their attention. Doctors would not have felt compelled to
try a pesticide based medication to test for an
arthropod. They wouldn't have occluded the skin rash to
attempt recovery of a parasite, nor have taken skin
scrapings, nasal aspirate, and eye exudate samples for screening.
To have overlooked parasitism may have kept the infection
beyond their reach.
Why did the outbreaks occur? The children and staff have always been
exposed to Megaselia scalaris uneventfully. This isn't to say
they were never parasitized before. It could have occurred
subliminally.What changed the situation had to be exposure to
excessive concentrations of larvae. It breeched their level of
tolerance and caused symptoms to appear. Excessive larvae
naturally point to breeding flies, but a phorid colony can be quite
surreptitious and very difficult to find.
*Sheila O'Leary is an active member of the National Unidentified Skin
Parasite Association (NUSPA). NUSPA advocates for
research into skin complaints, and skin-orifice complaints attributed
either to unknown causes or to Delusions of Parasitosis (DOP).
O'Leary's proposed, arthropod disease model is based solely
on her experience as a patient and that of others reporting to
the NUSPA site.
O'Leary suggests that the epidemics overlap with USP
and DOP in important ways. In each situation, females
are more likely to be affected than males. The cause(s) cannot be
isolated, and psychogenic factors enter the analysis. To assure
the public the outbreaks do not have a lasting
effect is merely a guess. If students have the
identical problems of USP/DOP patients in the acute phase, there
is a long range danger. Patients who become chronic are
always environmentally ill, and there is a suicide statistic attached
to chronic Delusions of Parasitosis.