Spider Bites - Diagnosis and Treatment

Diagnosis

Spotting a Black Widow

You’ll usually notice black widows by their shiny black bodies and those long, spindly legs. The most noticeable feature? That red hourglass mark on the belly’s underside.

Most of the time, the whole spider (legs and all) measures about 1 inch (2.5 cm) across.

Here’s a quick checklist for black widow spiders:

Feature	Description
Body Color	Shiny black
Special Marking	Red hourglass (belly)
Size	Around 1 inch (with legs)

If you spot a spider matching these traits nearby, doctors might use that info to figure out if a black widow bite happened.

Traits of the Black Widow Spider

People recognize black widows mostly because of the red hourglass mark. Female spiders usually have this marking. They hang out in dark, quiet spots like sheds or woodpiles.

Bites tend to happen when someone disturbs their hiding place.

What Doctors Look For

Even if you didn’t see the spider, your doctor can still make a diagnosis based on symptoms. Signs of a black widow bite can include:

Immediate pinprick or burning pain at the site
Redness and swelling around the bite
Muscle cramps or stiffness, especially in the abdomen or back
Sweating, chills, or nausea
High blood pressure or rapid heartbeat in more serious cases

Doctors will also ask about recent outdoor activity, especially around woodpiles, sheds, or dark corners—common spots for black widows.

If needed, they might run basic tests (like checking blood pressure or muscle tone) to rule out more serious complications.

Recognizing a Brown Recluse

BBrown recluse spiders have a golden to dark brown body and are best known for the violin-shaped mark on their back, near where the legs attach. Another unique feature: they have six eyes arranged in three pairs, instead of the usual eight.

Their body (not including legs) is small—usually about ½ inch (1.2 cm) wide. Brown recluses tend to live in quiet indoor spaces like attics, closets, and under furniture. Bites are rare and usually occur when the spider is disturbed.

Checklist for brown recluse spiders:

Golden to dark brown color
Violin-shaped marking on the back
Six eyes (arranged in pairs)
Small central body

Spotting a spider with these traits, or being bitten in a place where these spiders live, can help doctors determine if a brown recluse bite is likely.

Treatment

Medicine Used for Serious Black Widow Bites

Doctors sometimes turn to antivenom if someone has a strong allergic reaction or severe symptoms after a black widow bite. They give antivenom through a vein (IV). It helps ease serious pain or muscle cramps.

Most people feel better within about 30 minutes after getting antivenom. Since severe reactions can happen, doctors use this medicine only when it’s really needed.

Other treatments for spider bites include:

First Aid: Wash the bite with mild soap and water to help prevent infection. Put a cool compress on it for 15 minutes each hour to lower pain and swelling.
Pain Relievers: Over-the-counter meds like acetaminophen or ibuprofen help with pain.
Antibiotic Cream: Apply an antibiotic ointment three times a day to keep infection away.
Antihistamines: These medicines can calm down itching.
Antibiotics: If there’s an open sore or redness, a doctor might prescribe antibiotics.
Muscle Relaxants: These can help if muscle spasms show up.
Tetanus Shot: If you haven’t had a recent tetanus shot, your doctor may suggest one.

Surgery is pretty rare but sometimes needed if the bite causes serious skin damage or doesn’t heal well. Most bites—even from poisonous spiders—don’t require a hospital stay if you treat them quickly and carefully.

Getting Ready for Your Medical Visit

Steps You Can Take

If you think a venomous spider bit you, there are a few things you can do before seeing your doctor.

Safely catch the spider or snap a clear photo if you can do it without risking another bite. This helps doctors figure out the spider species and what treatment’s best.
Write down every symptom you notice, even if it seems minor—redness, swelling, pain, fever, or just feeling worse.
Make a list of questions you want to ask. You might wonder:
- Is this bite dangerous?
- Will I need extra tests?
- How long will recovery take?
- Will I need a tetanus booster or antibiotics?

Bringing all this info with you saves time and makes sure you get your questions answered.

Questions Your Healthcare Provider May Ask

Doctors will probably ask some key questions to figure out what’s going on. If you’re ready with answers, the visit goes smoother.

When did symptoms start and what were you doing before the bite?
How have symptoms changed since then?
What have you tried to ease the discomfort—like using a cool compress—and did it help?
Any history of bad reactions to bites or injuries?

That way, healthcare professionals can offer the right care or give advice on how to avoid spider bites down the road.

Spider Bites – Diagnosis and Treatment