Healthy Baby Practical advice for treating newborns and toddlers. Perianal Dermatitis: Much More Than Just a Diaper Rash Stan L. Block, MD, FAAP

iaper rash presents in a variety remove the diaper, you notice the eryth- of ways. Each case must be as- matous-based, slightly nonmacerated rash D sessed for the multitude of pos- of the perianal area extending slightly up sible etiologies or triggers for the rash. to the labia majora (see Figure 1). The rest The following cases explore important of her dermatologic examination is normal. causative etiologies an office practitioner Which test(s) should you perform next? will occasionally encounter. CASE 2 CASE 1 The mother reports to you that her You are seeing a 2 month-old-female healthy 4-month-old female has had some All images courtesy of Stan L. Block, MD, FAAP. Reprinted with All images courtesy of Stan L. Block, MD, FAAP. permission. for the first time for her well-baby checkup. pink of her diaper over the previ- Figure 1. A 2-month-old asymptomatic girl with She was a full-term, seven-pound, healthy ous 2 weeks, and yesterday she noted some perianal dermatitis extending to the labia. baby, born by spontaneous vaginal delivery, actual blood in the diaper. The child has whose mother had a positive Group B Beta been afebrile, eating well, and lacking any (GBBS) bacterial screen. constitutional or systemic symptoms. She The mother was treated with prophylactic has had no vomiting or diarrhea, her stools intravenous ampicillin, and the infant had are usually loose or soft since she has start- an otherwise normal newborn course. ed baby fruits this month, and the stools are The baby eats 6 to 7 ounces of standard not bloody. No one else in the family has milk-based formula per feeding and has been ill, particularly with any diarrhea. She about 5 to 7 wet diapers and 2 to 4 firm has never received any . stools daily. She has had no respiratory Your examination of the child shows a symptoms, fever, cough, or rash since birth. well-appearing, afebrile child with normal Your examination reveals a healthy look- growth parameters, tympanic membranes, Figure 2. A 4-month old girl who developed blood in her diapers over the past 24 hours along with the ing infant with normal growth parameters, pharynx, and neck. The remainder of her onset of obvious diaper dermatitis. tympanic membranes, nose, pharynx, and examination is normal except for the diaper neck. The heart, lungs, abdomen and ex- area with the rash seen in Figure 2. Which other family members have been recently tremities are normal. However, when you test(s) should you perform next? ill. She responds that the infant’s 8-year- old sibling was diagnosed with streptococ- Stan L. Block, MD, FAAP, is Professor of Clinical CASE 1 DISCUSSION cal last week. Should you also Pediatrics, University of Louisville, and University of Despite the newborn in utero perform a rapid strep test of the infant’s Kentucky, Lexington, KY; President, Kentucky Pedi- exposure from the mother’s GBBS prophy- throat? Possibly, but the yield is certainly atric and Adult Research Inc.; and general pediatri- laxis, the appearance of the rash just does almost none. cian, Bardstown, KY. not look like Candida. It is not purplish, You know that this rash in a 2-month-old Address correspondence to Stan L. Block, MD, and it does not have any satellite lesions. infant is not in any way typical for impe- FAAP, via email: [email protected]. Thus, you decide to order a routine bacte- tigo, yet you empirically prescribe amoxi- Disclosure: Dr. Block has disclosed no relevant rial “wound” culture for Group A strepto- cillin 40 mg/kg/day divided twice daily for financial relationships. coccus (GAS) by obtaining a skin swab of the infant based on your strong suspicion doi: 10.3928/00904481-20121221-05 the red rash. You also ask the mother if any of streptococcal perianal dermatitis (SPD).

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You do this despite this infant’s extremely you are unsure of the source of her infection young age for strep and a lack of reports because young infants rarely ever develop in the literature of this disease syndrome streptococcal pharyngitis. in newborns this young. After 48 hours, your suspicions are confirmed. The culture STREPTOCOCAL PERIANAL grows GAS. With your follow-up phone DERMATITIS (SPD) call to the mother, you are told that the rash In the past, SPD has been termed “peri- has now nearly disappeared. It appears that anal cellulitis” or inaccurately, streptococ- the infant had acquired the infection via her cal “proctitis.” The incidence of SPD ranges affectionate older brother’s kisses. He vis- from about 1 in 2000 to 1 in 200 patient vis- ited the office the next day with symptom- its.1 However, the most fascinating aspect Figure 3. A 9-month-old boy with typical Candida dia- per dermatitis with purplish hue and satellite lesions. atic pharyngitis and a positive strep rapid of these two cases is the very young age of antigen detection test (ADT). the children, as most series on SPD report a minimum age of 6 to 9 months.1,2 This very CASE 2 DISCUSSION erythematous and usually well-demarcated This 4-month-old girl’s rash (see Figure confluent rash of the perianal mucosa is a 2, page 12) appears to have well-defined superficial, noninvasive infection. However borders, and to be fiery reddened and mac- as Figure 1 (see page 12) shows, in younger erated, which likely accounts for the blood infants, the edge of the rash may not appear in the diapers. However, the edges of this as well demarcated. infant’s rash appear also to have some satel- Typical SPD starts at the anus and lite lesions. Is this Candida, or could this be spreads centrifugally, and sometimes up- Figure 4. A 6-month-old boy with typical multiple some impetiginous or folliculitis satellite le- ward to the vulva (see Figure 1, page 12) discreet pustular folliculitis lesions of Staphylococ- sions? With the history of blood in the stool, or to the scrotum/penis as well. It differs cus infection in the diaper region. you also might be concerned about the significantly from impetigo (summertime; possibility of an enteric pathogen-caused round, honey-crusted, or bullous lesions); school-age children with SPD. For exam- colitis, especially since your community is scarlet fever (fine discreet maculo-papular ple, a 10-year-old girl experiencing months recently experiencing a large Shigella out- rash starting initially in the groin, axilla, and of recurrent abdominal pain presented to break. However, the child’s stools are only abdomen); pustular folliculitis (usually a our office with new onset of blood in her occasionally loose. Thus, you are also not staphylococcal infection, see Figure 4); and stools. While withdrawing the colonoscope particularly alarmed about a possible Clos- erysipelas (a rash commonly on the face during a colonoscopy, the referral gastroen- tridium difficile toxin, especially with the and associated fever and ill appearance). terologist serendipitously noted the girl had lack of any previous antibiotic exposure. And unlike most other nondermatologic a characteristic erythematous rash on the As in Case 1, you elect to obtain a bacte- streptococcal infections, SPD does not pro- anal area. The patient had not complained rial wound culture of the infant’s perianal duce any constitutional symptoms such as of any anal issues, probably due to her age rash for potential streptococcal infection. fever or headache. SPD must also be differ- and/or embarrassment. An anal skin culture You have previously observed older infants entiated from candidiasis, pinworms, seb- was obtained and it grew GAS. The patient who had some bleeding in their diapers orrhea, and (rarely) sexual abuse. was treated with amoxicillin, and the rectal with similar perianal streptococcal dia- Recognition of SPD often depends on bleeding subsided completely. The colo- per rashes. The rash does not appear to be your distinct clinical gestalt and a high in- noscopy was normal, but the recurrent ab- typical for either candidal dermatitis (see dex of suspicion; it is particularly benefi- dominal pain persisted, likely due to com- Figure 3) or staphylococcal dermatitis (See cial to have confirmed a few cases of SPD. mon prepubescent ovarian discomfort (a Figure 4). You empirically initiate antimi- Typical characteristics of SPD are listed in pelvic ultrasound performed on the patient crobial therapy with amoxicillin at 40 mg/ the Sidebar (see page 14). was normal). kg/d administered twice daily for 10 days. Most children with this fiery red, peri- The culture result at 48 hours reveals GAS. anal SPD rash present with rectal itching or DIAGNOSIS OF SPD She does well on the antibiotic with no re- rectal pain as their chief complaint. Strep In Case 1, your colleague asks you currence of the infection. No other family pharyngitis is not commonly associated why you did not order a swab for an in- member had a likely streptococcal infec- with SPD either, although I personally have office strep rapid ADT of the infant’s rash. tion, such as pharyngitis or impetigo. Thus, observed it concomitantly in many younger You explain that first, in light of the young

PEDIATRIC ANNALS 42:1 | JANUARY 2013 Healio.com/Pediatrics | 13 Healthy Baby age and the maternal prenatal history, the consistently higher with the amoxicillin/ SIDEBAR. streptococcal rash could be Group B beta penicillin drugs than with beta-lactamase streptococci, and the ADT would not have stable drugs (odds ratio, 2.39). Typical Characteristics of detected this strain. Second, you happen to Feigin and Cherry’s Textbook of Pediat- Streptococcal Perianal be well-versed in the Clinical Laboratories ric Infectious Diseases4 suggests that these Dermatitis Improvement Act (CLIA), which can lead higher rates of recurrence in SPD are more Age: 6 months to 10 years to a fine of up to $10,000 for any inappro- likely a result of intra-familial transmission, Males: more common priate use of a laboratory test, even if it is and that evaluation and treatment of other Pruritis: 80% CLIA-waived. The in-office rapid ADT is family members may be necessary. In ad- Rectal pain: 50% only approved for pharyngeal testing. dition to Case 1, you personally have seen Hematechezia: 33% However, Clegg and colleagues2 showed this phenomenon in your office in a set Guttate psoriasis: rarely Family spread: common in a small study of 239 patients with extra- of 8-year-old twin boys, who had spread Source: Adapted from Nelson Textbook of Pediatrics1 pharyngeal strep infections, (73 cultures SPD to each other. For refractory SPD, from perineal sites) that 3 different strep- oral clindamycin or a cephalosporin plus tococcal ADT tests were accurate between rifampin also may be necessary.4 pect the rash of SPD via your gestalt of the 92% and 97% of the time, and that all the rash once you have confirmed a few cases. positive ADT tests correlated 100% of the COMPLICATIONS The rash’s appearance is usually typical (as time with bacterial culture. Unfortunately You suspect that in practice, these peri- seen in the figures), but be keenly aware (and fascinatingly), as part of the CLIA’s anal rashes are frequently misdiagnosed that SPD can occur in infants as young as “improvements,” if one performs an in-office and/or left untreated for weeks or even 2 months, as seen in Figure 1 (see page 13). streptococcal ADT, the results cannot be dis- months sometimes due to unwary parents I prefer to initiate therapy with amoxi- played in the chart or used to treat the patient. or clinicians. It is often misdiagnosed as cillin 40 to 50 mg/kg/day divided twice Repeat violators of this regulation could pos- “pinworms,” “diaper rash,” or “yeast.” You daily, once a “wound” culture for GAS of sibly be subjected to a $10,000 fine. worry that untreated streptococcal infec- the perianal mucosa has been obtained and So why not just send out the rapid ADT tions of the throat and impetigo of the skin a rapid strep ADT of the throat has been to a reference laboratory? For some strange as a group may lead to rare suppurative performed. An oral cephalosporin may reason, your experience has been that the complications such as lymphadenitis, cellu- be considered if you are observing a high results from a streptococcal culture return litis, septicemia, abscesses, or to rare auto- rate of streptococcal recurrences or if the just as fast as when the “rapid” ADT is sent immune complications such as acute rheu- child failed amoxicillin. Note that you must out to the reference laboratory. matic fever or acute glomerulonephritis. clearly label the transport media for the However, to my knowledge, this rash anal swab like you would for a “wound” TREATMENT OF SPD has not been associated with any of these or . Do not label it for a stool You know that either amoxicillin or rarer complications, even with very delayed culture, which may likely miss this strepto- penicillin would be the treatments of choice diagnosis. Nonetheless, during 30 years of coccal pathogen. Use of an anal rapid strep for GAS infections, and that no Streptococ- practice, I have observed only the follow- ADT to diagnose SPD is helpful, scientifi- cus isolate has ever been reported to be re- ing minor sequelae: scarlatini rash; anal cally sound, and very practical. But report- sistant to this class of drugs. But clinicians fissures; constipation due to painful def- ing it on the chart could be financially peril- who suspect a concomitant staphylococcal ecation; secondary guttate psoriasis; and ous during your annual CLIA audit. infection in SPD still should not prescribe as described above, possible unnecessary trimethoprim-sulfamethoxazole because endoscopic procedure. Group A streptococci are nearly uniformly Although rarely discussed in textbooks, REFERENCES resistant. Also macrolides, such as azithro- the other major concern during the evalua- 1. Kliegman RE, Stanton B, St. Geme J, Schor NF, mycin, should rarely be used, because of tion of a potential SPD rash is always the Behrman RE. Nelson Textbook of Pediatrics. 19th ed. Philadelphia: Saunders Elsevier; 2011. the frequent resistance of streptococci to possibility of sexual abuse or a sexually 2. Clegg HW, Dallas SD, Roddey OF, et al: Ex- this class of drugs. transmitted infection. Clinicians must con- trapharyngeal group A Streptococcus infection: A recent retrospective study of 81 chil- tinue to be vigilant, but SPD itself is not as- diagnostic accuracy and utility of rapid antigen dren with SPD by Olson and Bruce3 re- sociated with sexual abuse. testing. Pediatr Infect Dis J. 2003;22:726-731 3. Olson D, Edmonson MB. Outcomes in children ported a high rate of recurrence in SPD treated for perineal group A beta-hemolytic after treatment with either a penicillin drug CONCLUSION streptococcal dermatitis. Pediatr Infect Dis J. (38%) or beta-lactamase resistant antibiotic Thorough examination of all children 2011;30:933-936. 4. Feigin RD, Cherry J, Demmler-Harrison GJ, Ka- (28%). The meta-analysis of antibiotic fail- with any rectal pain, bleeding, itching, or plan SL. Textbook of Pediatric Infectious Diseas- ures in SPD showed the failure rate was also rash is paramount. You will strongly sus- es. 6th ed. Philadelphia: Saunders Elsevier; 2009.

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