'Unroofing' a Rare Toddler Rash

Healthy Baby Practical advice for treating newborns and toddlers.

‘Unroofing’ a Rare Toddler Rash Stan L. Block, MD, FAAP

CASE SCENARIOS Case #1 24-month-old male presents with a history of a 2-day rash A that his mother claims are “bug bites,” obtained when he was in the yard the evening before. He has been scratch- ing at the lesions, which are limited to his right arm (see Figure 1). He has had a “low-grade fever,” mild rhinorrhea, and a cough for a week but has been well otherwise. Earlier in the week, his sibling had a fever and sore throat, which had been diagnosed as herpan- gina, but no other family members have had a rash. The boy’s immunizations are up to date. All images courtesy of Stan L. Block, MD, FAAP. Reprinted with permission. All images courtesy of Stan L. Block, MD, FAAP. Upon physical examination, you ob- Figure 1. Maculo-papulo-vesicular crops of lesions noted only on the right arm of a 24-month-old boy. serve a cranky child who is well-nour- ished, active, and smiling. He has some Your differential diagnoses of the mild rhinorrhea, but a normal pharynx, skin lesions include: neck, lungs, heart, and abdomen. No • Insect bites other skin lesions are present on his • Early hand-foot-mouth syndrome body, including the hands and feet. • Shingles • Impetigo simplex Stan L. Block, MD, FAAP, is Professor of Clinical • Molluscum contagiosum. Pediatrics, University of Louisville, and University of Kentucky, Lexington, KY; President, Kentucky Pedi- Case #2 atric and Adult Research Inc.; and general pediatri- An 18-month-old white female pres- cian, Bardstown, KY. ents with a 4-day history of itchy, pain- Address correspondence to Stan L. Block, MD, ful rash on the right lower back (see Fig- FAAP, via email: [email protected]. ure 2). The mother reports the child has Disclosure: Dr. Block has disclosed no relevant been slightly cranky, with a “low-grade Figure 2. An18-month-old white girl with a 4-day financial relationships. fever” of 100°F, and says the child in- history of itchy, painful rash on her lower back. doi: 10.3928/00904481-20121018-05 jured herself on the playground slide (Note the incidental hemangioma on the left.)

452 | Healio.com/Pediatrics PEDIATRIC ANNALS 41:11 | NOVEMBER 2012 Healthy Baby

initially being small blisters. But the occurs before 20 weeks of gestation, fe- rashes in both cases have remained en- tal death or varicella embryopathy may tirely stationary since the first few days, occur.3 Also, neonatal varicella can be and you observed no honey-crusted le- fatal in up to 20% of infants whose sions. mother develops varicella within 5 days However, closer examination of both before or 2 days after delivery.1 cases (see Figures 3 and 4) sparks a Another article presented a single different diagnosis: shingles, or herpes case report in a 3-month-old with zoster zoster. Several clusters of small vesicles in a lumbar distribution;1 and a Span- are apparent throughout a distribution ish series of 16 children with zoster re- Figure 3. Close-up of lesions in Figure 1 (see page 452). Note the crops of red vesicles in a thoracic of one to three consecutive dermatomes ported five in utero exposures and two dermatome (T1) distribution, typical of herpes in the thoracic (T1) and lumbar (L3) unknown exposures. Interestingly, tho- zoster reactivation. regions, respectively. As you peruse racic dermatome distribution has been your textbook on dermatomes, you are observed in 65% to 75% of cases in two certain they have the distribution con- other series.2 sistent with shingles. Also, the linear pattern of lesions look quite character- ‘Unroofing’ Shingles (Herpes Zoster) istic for shingles lesions that are several Varicella zoster virus is a member of days old. However, you know that shin- the herpes family that causes two spe- gles in infancy is extremely rare. cific clinical syndromes: chickenpox You must also consider the possibil- and shingles. In the vaccine era, full- ity of eczemata herpeticum. No one in blown varicella infection in infancy and either patient’s family currently has or now childhood is very uncommon be- Figure 4. Close-up of Figure 2. Note the ulcers and has ever had symptomatic herpes, the cause most mothers have immunity to vesicles intermixed in an L3 dermatome distribution. No honey-crusted impetiginous lesions children have never had a history of the varicella virus and over 90% of the were present. eczema (nor will they 1 year into the pediatric population is vaccinated with future as you follow both patients), and the varicella vaccine between age 12 5 days before. The mother thinks that no preceding lesions or skin problems and 15 months.3 However, 15% to 20% these lesions may be abrasions. She was in the same area were ever noticed by of single-dose varicella vaccine recipi- also worried about the small blisters on the respective mothers. Neither child ents will still develop breakthrough the back, because a child in her day- had true fever or lymphadenopathy typ- chickenpox disease. It is usually much care had scabies and another child had ical of a primary herpes simplex skin attenuated and occurs within a mean of “MRSA.” The patient has been fully im- infection. 28 days after vaccination.4 munized. Where would the 24-month-old boy Herpes zoster, on the other hand, is a Your differential diagnoses of the and the 18-month-old girl have acquired reactivation of latent varicella virus that skin lesions include: varicella zoster virus without parental has remained dormant in the spinal gan- • Insect bites knowledge? Could it have occurred in glia for months to years, either after an • Shingles utero? You know that in order to mani- initial acquired varicella (chickenpox) • Traumatic abrasions with second- fest herpes zoster, the patient must first infection or more recently after immu- ary impetigo simplex have been infected with chickenpox; in nization with varicella vaccine. • Molluscum contagiosum with abra- rare instances a person may have as- The zoster rash concomitantly starts sions ymptomatic chickenpox before an out- with symptoms of pain, sometimes • Herpes simplex eczematum. break of zoster. burning and itching, and a maculopapu- lar, unilateral rash that over a few days DIAGNOSES AND DISCUSSION Infant Shingles evolves into an erythematous-based As you carefully examine the skin You remember having read an ar- vesicular rash that is nearly always lesions in Case #2, your first impression ticle previously about a few cases of distributed within one to three derma- is that these may be ruptured bullous infant shingles being acquired prena- tomes (see Figure 5, page 454). It is not impetiginous lesions because the moth- tally, without any damage to the unborn supposed to cross the midline. Howev- er had described a few of the lesions as child.1,2 However, if the fetal infection er, your Case #2 provides the exception

PEDIATRIC ANNALS 41:11 | NOVEMBER 2012 Healio.com/Pediatrics | 453 Healthy Baby

crease the pain associated with zoster.7 A closer inspection revealed the more vesicular characteristics of the rash in both children (see Figures 3 and 4, page 453). Although tempted to start an antibacterial for possible staphylococcal infection in Case #2, instead a bacterial skin culture was obtained and the child was asked to return in 2 days; the culture was negative at 48 hours. No signs of staphylococcal infection or scarring developed, and over the Figure 5. This 10-year-old boy presented with 3 days of painful burning and swelling on the right following year neither child has shown side of his face, before it erupted with the typical signs of recurrence, eczema, immune trigeminal dermatome zoster on day 4. Note the compromise, or malignancy, which has swelling and the clusters of vesicles on his right lower cheek, lip, and pre-auricular area. Figure 6. Uncertain diagnosis. A 3-year-old other- been a concern in the past. wise healthy white girl with vesicles, ulcers, pap- ules, and a mild secondary cellulitis on her left Although zoster develops much more to this “midline” rule as well as to the cheek. The lesion is most likely herpes simplex, frequently in children with neoplasms 5 but could be herpes zoster in the trigeminal nerve “age” rule (see Figure 2, page 452). dermatome. She had received a single dose of var- and organ transplants, conversely, the The duration of the first-time zoster icella vaccine at age 12 months. She was treated isolated occurrence of zoster in other- with oral acyclovir and oral clindamycin (for the rash may be from 1 to 3 weeks. Post- cellulitis). No diagnostic testing was performed wise healthy children is not associated herpetic neuralgia rarely occurs in chil- because it would not have affected management. with an increased risk of neoplasms.2 dren, unlike in adults.3 However, occa- sionally children may present without a to 41 months.1 Childhood zoster (> 12 VACCINE STRAIN-RELATED rash and with only pain and swelling, months old) usually occurs in those ZOSTER either for the first several days, or as the who became infected either prenatally Both children had received a single only manifestation (see Figure 5); this or within the first year of life.1 dose of varicella vaccine at age 12 is known as subclinical zoster or zoster The pediatric incidence of zoster has months, as is the custom in your of- sine herpete. been reported in the post-vaccine era fice. Neither child ever had a history of Sometimes, it is nearly impossible to as 0.2 to 0.74 cases per 1,000 person- chickenpox lesions. Thus, the rash in differentiate with any certainty due to years.2 But even during the pre-vaccine both cases was most likely due to vac- erythematous macules and vesicular le- era, the rate of zoster in those younger cine strain-related zoster. Despite your sions in a near dermatome distribution, than 5 years was reported as low as 20 consternation about the varicella vac- whether the rash is due to zoster or her- cases per 100,000.6 To my knowledge, cine normally protecting against zos- pes simplex (see Figure 6). Performing no post-vaccine era incidence data are ter breakthrough, the small clusters of polymerase chain reaction (PCR) or available for this age group. vesicular lesions were typical for mild culture by “unroofing” the lesions may zoster infection. be the only method of determination. CASES #1 AND #2 Post-vaccine–related zoster is mild- Although you have performed no vi- er, less readily transmissible, and in Pediatric Zoster ral diagnostic testing, such as PCR or the past, occurred less frequently than Infantile zoster (younger than 12 culture, “the diagnosis of herpes zoster wild-type virus–induced zoster;6 it is months old) is supposedly extremely is based on clinical judgment.”2 Empiric not due to vaccine failure. However, rare and usually results from mater- therapy could be initiated with acyclovir when using PCR analysis for 32 vari- nal prenatal varicella infection, which (80 mg/kg day four times a day) for 5 cella vaccinated cases of zoster (before may have been asymptomatic. In fact, days if you were concerned about pain the widespread routine use of varicella most young infants are protected from or zoster recurrence, the patient’s very vaccine), 22 cases were vaccine strain- varicella infection by transplacental young age, or whether these angry- related and 10 were wild-type virus.4 maternal antibodies to varicella. The looking viral lesions might trigger a The nearly universal varicella vaccine average patient age in such infections secondary bacterial infection. Early ad- policy of this decade, with its secondary is 12 months old, within a range of 2 ministration of oral acyclovir may de- “herd” protection, would likely signifi-

454 | Healio.com/Pediatrics PEDIATRIC ANNALS 41:11 | NOVEMBER 2012 Healthy Baby

cantly reduce the current incidence of developed any honey-crusted lesions or 2. Rodriguez-Fanjul X, Noguera A, Vicente A, wild-type virus–related cases of zoster. red streaks, the rash spread notably, or González-Enseñat MA, Jiménez R, For- tuny C. Herpes zoster in healthy infants Among leukemic children, the vac- fever developed. and toddlers after perinatal exposure to cine seems to be highly protective Management of either chickenpox varicella-zoster virus: a case series and re- against zoster when compared with or shingles typically consists of daily view of the literature. Pediatr Infect Dis J. 2010;29(6):574-576. those who had not received the vac- washing of lesions, oral antihistamines, 3. Pickering LK, Baker CK, Kimberlin DW, cine.6 At least two theories have been and pain medications as adjunctive Long SS (eds). Redbook 2012. Elk Grove proposed for why a reduced risk of therapy for children. Some experts rec- Village, IL: American Academy of Pediat- rics; 2012. zoster after varicella vaccine occurs: ommend acetaminophen only, avoid- 4. LaRussa P, Steinberg SP, Shapiro E, Vazquez 1) vaccine virus attenuation; or 2) the ing ibuprofen because of the arguable M, Gershon AA. Viral strain identification in usual absence of a rash post-vaccine, relationship between ibuprofen-treated varicella vaccinees with disseminated rash- which is important in order for the vi- varicella and group A streptococcal su- es. Pediatr Infect Dis J. 2000;19(11):1037- 1039. [Erratum in Pediatr Infect Dis J. 2001; 7 rus to travel into the dorsal ganglion perinfection. 20(1):33.] and become latent.6 Most healthy children do not routine- 5. Paller AS, Mancini AJ. Hurwtiz Clinical Pedi- ly warrant antiviral therapy for uncom- atric Dermatology: A Textbook of Skin Dis- orders of Childhood and Adolescence. 4th MANAGEMENT OF ZOSTER plicated zoster, at least after age 1 year. ed. Philadelpia: Elsevier Saunders; 2011. Due to the classic pattern and ap- Recurrences (4%) and post-herpetic 6. Schmid DS, Jumaan AO. Impact of varicella pearance of the lesions and the well- neuralgia are fairly rare in children vaccine on varicella-zoster virus dynamics. 8 Clin Microbiol Rev. 2010;23(1):202-217. appearance of both children, expen- too. And finally, pediatric uncompli- 7. Gershon AA. Varicella zoster virus. In Feigin sive viral testing was not performed. cated zoster infections are not associ- RD, Cherry J, Demmler-Harrison GJ, Ka- No antiviral therapy was prescribed, ated with malignancy or immune com- plan SL, eds. Feigin and Cherry’s Textbook which is the preferred course of action promise. of Pediatric Infectious Diseases, 6th edition. Philadelphia: Elsevier Saunders; 2009:2077. in children who are otherwise healthy. 8. Kliegman RM MD, Stanton BMD, St. Geme You elected to have the parents observe REFERENCES J, Schor NF, Behrman RE (eds). Nelson 1. Dent AE, Baetz-Greenwalt BA. Herpe- th the lesions closely over the next 7 days, Textbook of Pediatrics, 19 ed. Philadelphia: zoster in an infant. Clin Pediatr (Phila). Elsevier Saunders; 2012. and to return to the office if the child 2007;46(7):646-649.

PEDIATRIC ANNALS 41:11 | NOVEMBER 2012 Healio.com/Pediatrics | 455