P h o t o G a l l e r y
| The photos of
head lice here were taken with a macro lens camera. So what you see is a reasonably
magnified version of what must be searched for with the naked eye during an examination.
If you think any of the photos are a little rough and a little too far away to get a good
look at the critters, then that serves as a reminder of the scrutiny that is required to
make an accurate diagnosis. It is
advisable to find a live louse in the hair in order to confirm an active infestation.
While this is recommended before commencing treatment, it is much harder to be sure that
every single live louse is gone after treatment, especially in bulky hair. Research by
Bailey & Prociv suggests that underdiagnosis, or 'false negatives', is a major factor
in the spread of lice.
Click on any photo to see an enlarged
version.
 |
This is magnified about 3 times. Here you can see:
one egg on the hair (see the teardrop shape and eccentric attachment to the hair); one
small adult (this male is only 2.5 mm long); one 3rd instar (about 1.5 mm long); and one
2nd instar (just over 1 mm long). They are quite clear on a plain background, or in some
kids' sparse, pale hair; however, with other hair colours, layering and texture, they can
be very well hidden.
|
You can also see these well enough but they are
magnified 4 times. These lice are just over 1 mm in length and probably only 2nd instars.
They are easy enough to see on the palm of the hand here but in the hair it's a different
story. We haven't yet got to the baby lice - the first instars. These are usually thought
to be about 1 mm long. Actually, newly-hatched lice studied by Bailey and Prociv are
closer to half a mm. If they haven't taken their first feed, they are practically
invisible, blending in with skin flakes and dust and speckled lighting in the hair.
|
|
 |
| What are these?
Desquamative epithelial plugs ('pseudonits') can be loose and flaky or can be nearly
egg-like and encircle the hair shaft like beads. Please do not confuse them with eggs;
these skin plugs brush off or slide down the hair shaft with the lightest touch of the
finger. The most telling sign is that head lice eggs need the shearing force of a
fingernail to break the 'glue' and move them along. Some laypersons with experience
quickly get the hang of diagnosis. However, does that mean that all laypersons can
diagnose the course of infestations with certainty? Have a look at the next photo... |
This has
been taken against a plain cloth and already it's getting tricky. First you see a detached
egg on the left, then on another hair are two objects, including an egg on top, and
finally there is another egg on the hair on the right. Back to the two objects, the top
egg is easy to distinguish now, but what is the lower object? A flaky hatched egg ('nit')?
A flaky pseudonit? No, this is a newly-hatched head louse. About half to three-quarters of
a mm long. That's only about 1/32 of an inch. |
|
 |
| This kind of comb is a valuable tool to remove lice
more easily than the hands can. Adults with no carer to handpick lice and eggs for them
can use fine-toothed combs to self-diagnose and remove lice. However, can everyone be sure
if they are still infested or can stop combing? Can you see the tiny louse on the prongs?
Note, this photo is about double actual size. How about in the next photo... |
The same
view magnified about four times. A tiny louse is at the base of the lowest prong. The
resolution of the picture may not be adequate for you to see it. Neither is the visual
acuity of some people. Some health departmental policies have no or few screenings of
children in close-contact institutions. The underlying assumption is that everyone can
reliably check that they are completely cured, and if not, forward transmission from
long-term conditions is unimportant. |
|
 |
| Another
fine-toothed comb to make the job of removing lice from children's sensitive scalps that
much easier. If it's comfortable to use, then young children are more likely to cooperate.
Can you see the louse caught in the prongs? Is it the black thing between the 10th and
11th prong from the right side of the comb? Try magnifying it again... |
This is now magnified
four times. That's clearer. Or is it? The black thing is just fibrous fluff. The brown
elongated thing between the prongs to the left is a louse. Ideally the louse found should
be removed, rinsed and allowed to dry and poked at with a hair. If the louse grabs the
hair and then begins crawling deftly along it in mid-air, then even the inexperienced can
reliably conclude that it is not a hitchhiking insect from the garden or elsewhere. |
|
 |
| Here is a
first stage louse, together with 3 eggs for comparison. You'll note that the louse is
smaller in length than the eggs. It is quite clear here because it is magnified quite a
bit and it is a preserved specimen that had darkened before the photo was taken. Look
where the louse is sitting on the measuring ruler - between the two marks indicating a mm.
It is close to only half a mm! And it is photographed on a white background. Look what
happens when the same louse is put among just 10 black hairs. Now you see it… |
…now
you don't! Camouflaged in only a few hairs. (Anybody viewing these photos who suspects
that they have lice should seek expert diagnosis and only treat if live lice are found. If
you really have an infestation for the first time, you will probably be finding large,
obvious, moving live lice as a sign to begin treatment. Anybody who has just caught lice
will hopefully gain some insight into the care required. These photos are to invite
discussion about the complexities involved in diagnosis.) |
|
 > |
| Here is the same louse and eggs. Again, you can nearly
tell it is a louse and the eggs are reasonably obvious. Remember this is magnified, and
you can work out by how much by the mm marks. Also, it is against a clear background.
Laboratory examination is easy. However collecting lice for data collection is another
matter. Researchers cannot assume that if adult lice are found in the hair after a
presumed 'all-clear' that this indicates a reinfestation. Even large lice are
well-camouflaged. And, note that any missed small lice grow quickly to adult size within a
week. Have another look in the next photo. |
The same
louse and eggs among 20 brown hairs. Imagine that you are examining hair with the naked
eye, as parents must do, and that you are sifting through 100,000 hairs, which is about
the average number of hairs on the human scalp. If lice have already been treated in the
family and there is a suspicion of chronic or relapsing lice, then these photos are a
reminder that an unsuspected residual louse population may remain even after vigorous
attempts to remove lice. Bulky hair can make complete removal extremely difficult. The
photos underscore the difficulties that some laypersons may face after beginning
treatment. |
|
 |
| Now the view is getting closer to realistic. The louse
and eggs are on a plain background and are still magnified at least double. Already the
shapes are less obvious. |
Here, the
thumb of a woman's hand gives an idea of how enlarged the view is and yet already you are
losing sight of what you need to see in just 20 brown hairs. A fine-toothed comb will
assist removal from hair, but lice can evade a fine-toothed comb. What if no lice are
retrieved? What if eggs are near the scalp and ongoing symptoms indicate an active louse
infestation after treatment? A bright light and lens may be needed to have a good look for
any signs of moving lice. If visual confirmation is difficult, then follow-up is
important. |
|
 |
| Head lice fallen on smooth skin will be brushed away
in a second and doomed to die without the host. However, what could happen if people were
thrust into an unfortunate situation where hygiene is non-existent, hospitals are
non-existent, clothing is never changed and where head lice are extremely neglected?
Notice the skin condition. Notice the eggs. Also, notice the barely visible object to the
left, which, in real life looks like a barely moving minute freckle. Depending on the
background, young head lice can be more difficult to identify than their eggs. |
Again see the thumb that indicates the magnification
of this picture. Aside from the eggs, again, can you make out the object to the far left
of this picture? Having an awareness of the varied appearance and movements of lice during
development and during both parasite and host-mediated behaviours will assist in clinical
diagnosis, rearing experiments, and an overall understanding of the biology of human lice.
Great care is needed to conduct accurate studies on the settlement, habitat site choice
and oviposition behaviours of lice. More research on the basic biology of lice is
indicated. |
|
|
|
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
\"/
=( )=
{ }
|