Peeling rash in a 4-year-old boy

The Case

The mother of a 4-year-old boy, whose family recently emigrated from Haiti, brings him to the pediatric mobile clinic for evaluation of a rash that had begun 11 days earlier as an eruption of vesicular, pruritic papules on the bilateral lower extremities and had spread to the buttocks and medial thighs with sparing of the face. The skin eruption was followed by desquamation of the skin on his palms and soles. 

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Prodromal symptoms included 3 days of nasal congestion, rhinorrhea, and subjective fever. The patient’s past medical history was significant for childhood obesity.

Initial physical exam revealed symmetric, diffuse 2-mm to 4-mm grey-brown flat-topped papules with subtle surrounding desquamation that extended from the hands and feet centrally, including medial thigh, buttocks, and occasional lesions on the torso (Figures 1 and 2). The palms and soles exhibited peeling of the superficial layers of skin, revealing raw, mildly erythematous tissue (Figure 3). No oral lesions or exudates, conjunctivitis, or lymphadenopathy were noted, and the remainder of the examination was noncontributory.  

Differential diagnosis

Despite an extensive list of acute childhood exanthems, the possible etiologies of fever and rash in the patient were narrowed down to hand-foot-mouth disease (HFMD), varicella, post-streptococcal rash, and herpes simplex virus (HSV). (See Table^2-3).

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The index of suspicion was highest for HFMD, a viral exanthem most commonly caused by coxsackievirus A16 (CVA16) and enterovirus 71 (EV71).¹ Classic HFMD is characterized by fatigue, sore throat/mouth, and a typical cutaneous eruption most significant on the palms, soles, and distal extremities.¹ It most commonly affects preschool-aged children with the highest incidence rates during the summer and fall in temperate climates.¹ Ulcerative lesions initially appear on the buccal mucosa and hard palate following a prodrome of fever, muscle aches, and fatigue. Several days later one will notice the development of vesicles on the hands, feet, extremities, and buttocks that can be painful and itchy.¹ The patient exhibited the classic skin findings of HFMD; however, he denied a sore throat, and no ulcerative lesions were noted on the oral mucosa. Yet, the lack of an oral exanthem did not rule out the diagnosis of HFMD as cases presenting with solely cutaneous findings have been reported in the literature.¹

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Varicella, more commonly known as chicken pox, begins with a low-grade fever and fatigue, followed by the development of an intensely pruritic rash characterized by little fluid blisters on a red base (“dew drops on a rose petal”).² The rash usually starts on the face and trunk, eventually spreading to the arms and legs with involvement of mucous membranes as well. Lesions are often found in various stages as new crops of vesicles erupt and crust over in successive pattern every few days.² Initial concern for varicella was heightened because the patient was unimmunized upon arrival to the United States and had only received the first dose of the varicella vaccine series less than 5 months prior to rash onset. At the time of his sick visit, he was due for his second catch-up dose; however, the decision was made to withhold required vaccinations until the rash improved. Despite the patient’s vaccination status, inoculation with varicella was unlikely in this patient given the location, pattern, and spread of the lesions. He also exhibited extensive involvement of the palms and soles with sparing of the trunk and face, which is uncommon for varicella.

Scarlet fever is a childhood exanthem that results from infection with group A beta-hemolytic streptococci (GABHS) and subsequent release of a pyrogenic exotoxin.³ The prodrome consists of 1 to 2 days of fever and sore throat followed by the appearance of a generalized, erythematous, fine papular rash that is often referred to as sandpaper-like in texture.³ The rash typically begins on the trunk and then spreads throughout the body, often sparing the palms and soles.³ The rash begins to fade several weeks after onset and is followed by desquamation of the skin, this time including the palms and soles.³ This patient presented with extensive, painful desquamation of the hands and feet several weeks after his mother first noted the rash. However, the evidence against scarlet fever in the patient was stacked and included the fact that the rash was vesicular in nature, involved the palms and soles with sparing of the trunk face, and was pruritic.

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First-episode oropharyngeal infection with HSV is commonly referred to as primary gingivostomatitis.⁴ Toddlers aged between 1 and 3 years are most commonly affected.⁴ Oral vesicular lesions typically develop following an average incubation period of 4 days and can be seen on the hard palate, tongue, gingiva, and around the lips.⁴ These fragile vesicles quickly rupture, leaving ulcers on an erythematous base.⁴ Other associated symptoms include fever, sore throat, anorexia, cervical adenopathy, drooling, and mucosal edema.⁴ If drooling is excessive, lesions may develop on the chin and neck as well.⁴ Generally a self-limiting illness, HSV infection lasts up to 3 weeks.⁴ Although the patient exhibited clusters of vesicular lesions similar in appearance to those of HSV, he had no evidence of oral or gingival involvement, making primary HSV infection highly unlikely. In laboratory testing, a rapid streptococcal A screen was ordered and returned positive.

Dermatology consultation

Dermatology was consulted, and 1 week later its report stated the “most likely” diagnoses of resolving viral exanthem with palmar and plantar desquamation/peeling and dry skin/xerosis (Figure 4). Dermatology recommended application of 2.5% hydrocortisone ointment to control the itching and emollient therapy. In addition, the mother was advised that the palms and soles would continue to desquamate as the rash resolved. Follow-up in 2 weeks was recommended.

NEXT: Course of treatment

Course of treatment

Although the diagnosis of a viral exanthem was high on the differential diagnoses, because of the desquamation of the hands and feet and the positive rapid strep screen, the patient was treated with a 10-day course of amoxicillin. However, the positive rapid strep test might have served as a marker of colonization in the patient. In this case, the peeling might have been related to the widespread primary viral lesions on the distal extremities and unrelated to streptococcal infection.

Although there was clinical debate as to the possibility that the patient could be a chronic GABHS carrier, it was decided to proceed with treatment. The boy returned for a follow-up exam approximately 2 weeks after the initial presentation. Reevaluation of his skin revealed numerous macular hyperpigmented lesions over the lower and upper extremities with involvement of the buttocks and thighs. In addition, desquamation of the palms and soles with mild erythema was still evident. The patient no longer complained of pruritus or pain and the rash appeared to be resolving. No other significant findings were noted on physical exam. Throat culture performed at this visit was negative for GABHS. The parent was reassured that the rash would continue to resolve and no further treatment was necessary.

One month later, the patient’s concerned mother brought him back to the mobile clinic because she had made a troubling new finding: His nails had begun to fall off (Figure 5). Pertinent physical exam findings included desquamation of the nails on both the hands and toes as well as evidence of hyperpigmented macules of the bilateral lower and upper extremities. The macules were consistent with residual postinflammatory markings of a resolved exanthema (Figures 6 and 7).

Discussion

In the United States, CVA16 and EV71 are the most commonly implicated infectious agents associated with HFMD.⁵ Recently, however, atypical cases of HFMD linked to an uncommon strain of coxsackievirus, specifically CVA6, have been reported worldwide, initially in China and the far East.¹ Atypical cases are characterized by unique clinical manifestations, such as extensive cutaneous disease variants, palmoplantar desquamation, and perioral lesions. Coxsackie A6 was initially discovered as the predominant virus responsible for an epidemic of HFMD in Finland and Singapore in 2008. Initial outbreak of CVA6 HFMD in the United States was not reported until 2012. The CVA6 subtype is characterized by unique dermatological findings, including delayed nail changes following the acute phase of the illness, less mucosal involvement, and widespread vesiculobullous eruption that extends beyond the typical palmar and plantar distribution of classic HFMD.

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Nail desquamation, formally known as onychomadesis, is characterized by separation of the proximal nail plate from the matrix most commonly followed by eventual shedding from the base.⁶ Onychomadesis is associated with numerous conditions including Kawasaki disease, epidermolysis bulla, and streptococcal infection; however, the most commonly implicated infectious etiology is HFMD. Although numerous serotypes of coxsackievirus are associated with onychomadesis, research suggests that CVA6 strain may be the major culprit. On average, nail findings become clinically evident 4 to 10 weeks postinfection. There is no specific treatment for this condition and prognosis is good as eventual regrowth of nails occurs spontaneously in a vast majority of cases.⁷

NEXT: Diagnosis, treatment, follow-up

Because of the dermatologic findings and pattern of secondary sequelae from the initial presentation, as well as the positive GABHS test, the suspicion was high that this patient had a coinfection of GABHS and coxsackievirus infection. Very limited research exists on the clinical manifestations of coinfection with coxsackievirus and GABHS. A study conducted by Egyptian researchers nearly 30 years ago attempted to bridge the link between GABHS, coxsackie B virus (CBV), and rheumatic fever.⁸ The researchers postulated that CVB may serve as a cofactor in the development of rheumatic fever following infection with GABHS.⁸ Although they found that patients with acute rheumatic fever were more likely to be coinfected with CBV and GABHS versus GABHS alone, they failed to demonstrate a clinically significant correlation.⁸ Thorough literature review has failed to reveal any cases documenting the potential sequelae, particularly in regard to cutaneous manifestations, of coinfection with GABHS and coxsackie A virus (CAV). More research is required to examine the role of GABHS serving as a cofactor for the development of more significant cutaneous disease.

Diagnosis, treatment, follow-up

Classic HFMD caused by CVA16 and EV17 was once the predominant presentation in pediatric offices across the United States; however, pediatricians are finding that the CVA6 presentation may be the new typical HFMD. Classic HFMD is primarily a clinical diagnosis because the disease presents with such a classic appearance and location of the cutaneous and oral lesions.⁵

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Primary care physicians generally diagnose the condition without confirmatory viral testing or dermatology consultation. However, given the rise in the atypical form of HFMD, it may be wise for clinicians to become familiar with laboratory techniques that allow for detection of the specific viral serotype, such as stool samples, throat swabs, and reverse transcription-polymerase chain reaction (RT-PCR) testing of vesicular fluid.⁵ As of yet, no antiviral therapy has been developed for the treatment of HFMD. Supportive therapy, particularly hydration and pain control, is the treatment of choice as the disease is generally self-limited in nature.¹ Strict adherence to hand hygiene protocols is imperative in limiting the spread of the virus and future inoculation as it is mainly transmitted via fecal-oral route.¹

Patient outcome

The patient has since returned to the clinic for routine vaccinations, at which point in time his nail findings had resolved and a point-of-care strep test was negative, thus eliminating the possibility that the patient was a carrier.

REFERENCES

1. Ventarola D, Bordone L, Silverberg N. Update on hand-foot-and-mouth disease. Clin Dermatol. 2015;33(3):340-346.

2. Sethuraman G, Bhari N. Common skin problems in children. Indian J Pediatr. 2014;81(4):381-390.

3. Allmon A, Deane K, Martin KL. Common skin rashes in children. Am Fam Physician. 2015;92(3):211-216.

4. Kimberlin DW. Herpes simplex virus infections in neonates and early childhood. Semin Pediatr Infect Dis. 2005;16(4):271-281.

5. Lott JP, Liu K, Landry ML, et al. Atypical hand-foot-and-mouth disease associated with coxsackievirus A6 infection. J Am Acad Dermatol. 2013;69(5):736-741.

6. Hardin J, Haber RM. Onychomadesis: literature review. Br J Dermatol. 2015;172(3):592-596.

 7. Nag SS, Dutta A, Mandal RK. Delayed cutaneous findings of hand, foot, and mouth disease. Indian Pediatr. 2016;53(1):42-44.

8. Zaher SR, Kassem AS, Hughes JJ. Coxsackie virus infections in rheumatic fever. Indian J Pediatr. 1993;60(2):289-298.

Ms Schermer is a third-year medical student at the University of Miami Leonard M. Miller School of Medicine, Miami, Florida. Dr Gwynn is assistant professor of Clinical Pediatrics and director of the pediatric mobile clinic at the University of Miami Leonard M. Miller School of Medicine, Florida. The authors have nothing to disclose in regard to affiliations with or financial interests in any organizations that may have interest in any part of this article.