Be careful before petting that caterpillar!

Saddleback Caterpillar. Image courtesy of Keegan Morrison, wikipedia user.

Continuing the theme of insects, here’s a post on… caterpillars! Caterpillars might be colorful and cute, but some of them can cause you pain if you touch them!

Some caterpillars like the puss caterpillar (looks like a pussywillow), saddleback caterpillar (it’s back does look like a saddle!), brown-tail moth caterpillar, io moth caterpillar, crinkled flannel moth caterpillar, Douglas fir tussock moth caterpillar, and flannel moth caterpillar can cause a rash with their hairs. The cocoons can also have these toxins.

Puss Caterpillar.

So in short, just because a caterpillar looks cute or has a cute-sounding name, it doesn’t mean that you should pet it!

What are bed bugs?

Photo of a bedbug.

There’s been a lot of press on bed bugs in hotels and I’ve definitely had patients come in who had stayed in a random hotel only to wake up the next day with itchy welts on the skin.

Heck, there’s even a bed bug registry to check whether your apartment, hotel or motel has had cases of bed bugs.

So what are bed bugs?

They are little bugs with flat oval bodies which feed on blood. They have fancy names too, e.g. Cimex lectularius and Cimex hemipterus. They often feed when you’re sleeping, coming out and feeding on your blood by puncturing your skin with their mouth parts. They inject a little bit of anesthetic into your skin too so that you don’t feel the bite. Sneaky!

These bed bugs can crawl through cracks and crevices so if a neighboring apartment or hotel room is infested, yours can become infested too.

If you’re concerned, you might want to call an exterminator. There are also special stands for your bed post.

Lastly,¬†here’s a random fact about bed bugs. Do you know how they mate? It’s by a process called traumatic insemination, where the male bedbug punctures the female bedbug’s body directly and injects the sperm directly into the female bedbug’s body.¬† Now that’s TMI about bedbugs…

How do you prevent razor burn?

After shaving, it’s common to develop irritation of the skin and bumps over the skin. How can you prevent razor burn? Here are some common and uncommon tricks to prevent razor burn.

Make sure your razor is clean. Overuse of the razor can make it more likely to nick your skin and introduce bacteria.
Shave in the direction of the grain of the hairs. This means that shave in the direction that your hairs are growing out. Shaving against the grain causes more irritation.
– Use a shaving cream or shaving gel.
– If you are going to reuse the razor, 1) rinse it well after use, 2) dip it in some rubbing alcohol to decrease the microbes on it, and 3) store it in a clean place with the blade facing up. Always be careful to “guard” the razor blade so that you don’t cut yourself.
– After shaving, use a benzoyl peroxide wash (e.g. Clean & Clear acne wash, Pan-Oxyl wash or bar, etc). This can decrease the likelihood of the bumps (folliculitis) after shaving.
– If you have clindamycin gel (a prescription medication which is used for acne), you could rub it onto the skin if little bumps do develop.

What is the cold spray that your dermatologist uses?

Courtesy of wikipedia user Warfieldian.

For those of you who may have seen your physician for warts, barnacle growths (seborrheic keratoses), actinic keratoses (pre-cancers caused by sun) or even some skin cancers, you may have experienced cryotherapy. Cryo refers to cold, and cryotherapy is a method by which cells are destroyed by extreme cold temperatures down to -196 degrees celsius!

Most commonly, physicians use liquid nitrogen which is then sprayed through the canister in the photo above and turns into a gas outside of the canister. This stream is directed at the target to be destroyed!

Cryotherapy stings (at least in my patients’ and my experience). Afterwards, your skin might be red and you might get a blister or some crusting. This should heal up but if you have concerns after treatment, let your physician know.

So now you know a little more about that scary looking can that your physician may have sprayed you with!

Why does your scalp itch?

Image produced by Frank Gaillard

An itchy scalp is a relatively common complaint in the dermatologist’s office. Sometimes, a rash of the scalp is visibly present, but other times, the scalp can look completely normal making it quite difficult to tell what the cause of the itchy scalp is!

So here are some causes of an itchy scalp with a rash:

– Seborrheic dermatitis – Dandruff is a variant of this as is cradle cap in infants. The scalp is often red with greasy yellow scale.
– Psoriasis – Patients often has psoriasis elsewhere on the body too. Red areas are present with drier whitish or silvery scale.

Here are some causes of itchy scalp with visible change of the scalp and hair loss:

– Frontal fibrosing alopecia
– Central centrifugal cicatricial alopecia
– Lichen planopilaris

(These are rare so don’t go diagnosing yourself!)

Infections of the hair follicles can lead to itchy scalp too. e.g. infection by bacteria, fungus, or mites.

There is definitely a strong neuro-derm component to itchy scalp as well. Researchers have found a close association of nerve endings with hair follicles — so there’s an anatomical reason as to why you might have itching of the scalp but not of other areas of the body.

Regardless, if itchy scalp is something that you are struggling with, see your dermatologist. Dermatologists are doctors of the skin but also of the hair and nails!