Mysterious Rash 10 days AFTER bumping a reef

[DocVikingo]

I'm not a doctor, but I do want to raise three questions as part of the diagnosis you are working on....Have you ever had psoriasis?

Hi openmindOW,

Psoriasis typically manifests as red/pink areas of thickened, raised, and dry, often flaky, skin.

Essentially any body area may be involved, but it typically affects areas over the elbows, knees, and scalp. It is a long duration/chronic condition with onset most common in the 15-25year old range,

As we're fond of saying in medicine, "If it looks like a duck, walks like a duck and quacks like a duck, it probably is a duck" ; )

No need to reach into the conjectural dermatological stratosphere in this inquiry.

Regards,

Doc

[DocVikingo]

Hi Dawn,

It's very likely that the skin disturbance described is the result of contact with stinging hydrozoans or anthozoans, such as the so called "stinging hydroids" or so called "fire coral."

It appears you were aware of the envenomations at the time they occurred, but didn't develop a full blown reaction until about 10 days later. Such delayed reactions are not uncommon. Just 4 days ago I heard from a chap who was diving the Caribbean and received stings while descending an anchor line (notorious for growing an abundance of hydroids). While reportedly aware of the stings when they happened, a notable allergic skin reaction wasn't evident until about a week later.

As Vlad the Impailer pointed out in his post above, it is not uncommon for the rash, itching and burning to recur after the signs and symptoms initially subsided. This is because antigenic material (e.g., tiny fragments of coral or hydroid “feathers”) can remain in the wound. Also, a cyclic immune response (redness, inflammation, itching, and swelling, itching or burning) can persist for weeks after the incident, sometimes longer.

In the meantime, some divers find the best bet to be an OTC antihistamine like loratadine (Claritin, 10 milligrams) or cetirizine (Zyrtec, 10 milligrams) taken as directed, although they can be mildly sedating. A topical preparation such as Benadryl (diphenhydramine) cream/ointment can help reduce itching. However, essentially gentle care and tincture of time are the best medicine.

In serious cases prescription antihistamines like Atarax or Vistaril, or oral steroids such as prednisone, may be directed by a doctor, but the situation described does not appear to warrant such treatment at the moment.

The condition should be carefully monitored and if the reaction appears to be getting significantly worse, or infection seems to be developing (always a worry with these scrapes/rashes), a dermatologist should be consulted as quickly as feasible.

It should be mentioned that the immediate treatment of such stings is rinsing the affected areas with copious amounts of plain white distilled vinegar. It's surprisingly effective, but will do nothing beneficial 10 days after the envenomation.

Best of luck.

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.

[Charlie99]

I've had long delayed reactions like you describe when I touched poison oak.

The treatment of the symptoms for fire coral and stinging hydroids are similar to that for poison ivy or poison oak. My recommendation is to use whatever worked for you with poison ivy.

My treatment of choice is external application of Benedryl gel on top of 1% hydrocortisone ointment (not cream). It makes a gooey mix that adheres to the skin and gets absorbed into the affected area.

YMMV.

[Jax]

Thanks, guys. Cozumel. Two incidences of assumed fire coral during the week. Red bumps now, which is roughly seven days later.

Using Benedryl. Will try the hydrocortisone ointment, too.

[Jax]

Charlie99 has the answer!

The "Benedryl gel on top of 1% hydrocortisone ointment (not cream)" is a winner!!!!

Red spots are still there, slightly raised, but thoroughly lessened by the treatment.