What Insect Bite Leaves Red Welt With A Black Core?

Posted on Wed, 29 Jul 2015

Question: I request a meaningful reply identifying the cause of the 'bites' causing a red welt with a bla. ck core. With reference to attached picture

Answered by Dr. Charu Bansal (10 hours later)

Brief Answer:
kindly give following details

Detailed Answer:
Hello. Welcome to Healthcaremagic.com.
I have read your query.
I understand your concern.
I have seen the attached photograph also. Though the image is not so clear.
I will like to know following details -
1 ) For how long you are having such lesions?
2) What are the sites of involvement?
3) How do they start and what is the course of progression?
4) Are these recurrent or only.single episode took place ?
5) Do they resolve spontaneously?
Kindly give answer to above mentioned questions and upload more pics.
Thanks

Above answer was peer-reviewed by : Dr. Shanthi.E

Follow up: Dr. Charu Bansal (6 hours later)

1 Not lesions but 'bites' or 'stings rrogress with raised red aising a welt.
2 Forearms and thighs.
3 Start with 'bite' (not felt) progress with raised red/pink raised circle about 15mm
diameter with black core (like large blackhead) removed by squeezing. Welt is painfully itchy and remains so for a week or so
4 Single episodes, sometime two within a week and some a week/10 days apart.
5 Painful gradually eases over a week/ten days.

Answered by Dr. Charu Bansal (15 hours later)

Brief Answer:
insect bite dermatitis

Detailed Answer:
Hello. Welcome back.
As per details, it seems that you are having a condition called insect bite dermatitis.
There are some insects which initiate allergic reaction leading to Urticarial rash followed by central crust or core representing the site of bite. At times, the allergy is so severe that even at the sites where no bite was there , similar rash appears.
in such cases, I prefer to advise topical antibiotic cream like mupirocin 2 percent over the affected area followed by a combination of antibiotic and steroid like hydrocortisone.
Also antihistaminics are started like levocetrizine.
You should visit your doctor so that he can examine you and give you prescription accordingly.
You can share my opinion with him. I hope it helps.
Take care.

Above answer was peer-reviewed by : Dr. Prasad

Follow up: Dr. Charu Bansal (8 hours later)

What are 'some insects'?

Answered by Dr. Charu Bansal (15 minutes later)

Brief Answer:
various species of beetle

Detailed Answer:
To be more precise, it is also known as Beetle dermatitis. There are various families and species of beetles which when bite a person leave their secreations which act as irritant leading to wide variety of lesions.
The usual presentation is urticarial rash with central crust representing the site of beetle bite.
They are more common in rainy and summer season.
I hope I am able to solve your query.
If you have any further query, you may ask me.
Stay healthy.

Above answer was peer-reviewed by : Dr. Vaishalee Punj

Follow up: Dr. Charu Bansal (2 hours later)

But the black core is not a crust and can be squeezed out like a oversize blckhead.

Answered by Dr. Charu Bansal (1 hour later)

Brief Answer:
central punctum can be squeezed

Detailed Answer:
Presentations vary and are not similar always. At times, only a central punctum is formed at the site of bite which can be easily squeezed or plucked out.
This is the most likely scenario in your case.
THANKS

Note: Hope the answers resolves your concerns, however for further guidance of skin related queries consult our Dermatologist.Click here to book a consultation

Above answer was peer-reviewed by : Dr. Neel Kudchadkar