Toddler presents with blisters on right hand

What’s your diagnosis?

A. Blister beetle injury

B. Chigger (Eutrombicula alfreddugesi) bites

C. Eczema herpeticum

D. Shingles (varicella-zoster)

Answer and discussion:

This is a child with moderately severe eczema and secondary herpes simplex virus infection on the damaged skin of his hand (answer C, eczema herpeticum). There are many manifestations of this condition, from localized to widespread, from mild to severe, sometimes requiring hospitalization. If you have a child with significant eczema, you know how difficult it can be to “stay ahead” of the inflammation with daily moisturizing and topical anti-inflammatory medications. From time to time, we all periodically let down our guard, and the skin can flare with a vengeance. Should that occur at a time of contact with HSV, or reactivation of the virus, manifestations will appear accordingly. The rash began responding within 48 hours to oral acyclovir and intensification of the patient’s eczema therapy (Figure 2, at 72 hours). Other cutaneous viruses can appear very similar when infected skin is damaged, such as coxsackievirus (eczema coxsackium) and the molluscum contagiosum poxvirus. The focus of management should always begin with treating the underlying problem as well as the HSV. One may not be able to visually distinguish between HSV and coxsackievirus without testing. If unclear, PCR testing of a lesion for enterovirus (coxsackievirus) and HSV should quickly give an answer.

Figure 2. Photo taken about 72 hours later, showing some resolution. Source: James H. Brien, DO.

The male blister beetle, when disturbed, or after mating with the female, will excrete a substance (cantharidin) that will result in fairly deep, blistering sore on the skin wherever it comes in contact (Figure 3). In the insect world, this substance is used to cover the eggs laid by the female of the species, for protection from predators.

Figure 3. Acute blister beetle injury. Source: James H. Brien, DO.

While not FDA-approved, in the medical world, it is sometimes used by dermatologists and veterinarians for treatment of various lesions. Healing of a sore is slow, leaving behind a scar (Figure 4). Images of various blister beetles can be found on the internet.

Figure 4. Blister beetle injury scar 2 months later. Source: James H. Brien, DO.

The chigger is a type of very small mite (Eutrombicula alfreddugesi) that will take a blood meal, then leave, unlike the scabies mite that burrows into the skin. The result of the bite is intense itching, probably due to the saliva of the insect. They are commonly called “mower’s mites” or “harvest mites.” In adults, they are typically on the lower leg areas, but in children, they can be anywhere. In young boys, they seem to favor migrating to the groin for their blood meal, oftentimes resulting in massive but harmless swelling of the highly vascular tissues proximal to the glans (Figure 5). This often looks like a need for catheterization, but it really doesn’t because of the soft nature of the swelling, making it look worse than it is. The best treatment is time and perhaps an oral antihistamine. If scratched enough, it can result in a secondary infection.

Figure 5. Acute swelling from chigger bites. Source: James H. Brien, DO.

Shingles is the rash caused by the reactivation of varicella-zoster virus, and when not in a typical dermatomal pattern, can look the same as a cluster of cutaneous HSV lesions (Figure 6). While not common in children, it does occur, and can be typical or atypical with lesions that may be scattered across the midline. Usually, treatment is of limited benefit unless the patient is immunocompromised. Consult your current Red Book for recommendations.

Figure 6. Shingles. Source: Col. Tom Murphy, USAF (retired).

Columnist comments:

As children are now back in school, hopefully with immunizations up to date, including COVID-19 and influenza, we can all transition into the winter with just a few less things about which to worry. I doubt that there are any providers who are against immunizations who read my column, but if you happen to be one, I would implore you to just take time to review the history of vaccine-preventable diseases through the last 100 years and the devastating effects on the health of their victims and their family and loved ones. When my wife and I visit our small hometown where we both grew up, we often take long walks through the city cemetery, reading the grave markers, which range from little more than a piece of cement to large, elaborate statues, which date back to the early 19th century. These engraved monuments often give the cause of death, especially those of young adults and children. Children’s markers are usually smaller, as are their grave sites. The markers often have a puppy or a kitten curled up on top, or perhaps an angel, with a heartbreaking epitaph (Figure 7).

Figure 7. Nineteenth century grave of a 3-year-old boy named Benjamin with the inscription, “Our darling boy gone so soon.” Source: James H. Brien, DO.

Space prohibits showing more. It is known that diphtheria, tetanus, smallpox, blood poisoning (sepsis and meningitis), influenza, measles and polio (to mention just a few) killed or crippled countless babies and children. If the epidemiology was the same today as it was then, the outcry would be deafening, to demand that something be done. Well, something was done, and we benefit today by those advances in immunizations. If you are still against immunizations, you need to have a reason that rises above the benefits that have been achieved, with many, many fewer babies and children in graves.

For more information:

Brien is a member of the Healio Pediatrics and Infectious Disease News Editorial Boards, and an adjunct professor of pediatric infectious diseases at McLane Children's Hospital, Baylor Scott & White Health, in Temple, Texas. He can be reached at jhbrien@aol.com.