Case Study: Telemedicine From the President

The following case study was used by James P. Keating, MD, MSc, medical director, St. Louis Children’s Hospital Diagnostic Center, and his co-editor, Andrew J. White, MD, division director of pediatric rheumatology/immunology, as part of the “Patient of the Week” (POW) series. Many of the POW case studies cover uncommon illnesses, or common illnesses with unusual symptoms that can be overlooked. If you would like to be added to the POW e-mail distribution list, send an e-mail message to jkeating@wustl.edu or white_a@wustl.edu.

Ped: Claudia Preuschoff,president, Missouri Chapter of AAP (Poplar Bluff)
Diagnostic Center: Drew Grimm/Jim Keating
Dermatology: Susan Joy Bayliss

Au: Drew Grimm

4-year-old boy with CC: rash and photosensitivity
HPI/PMH: Two weeks PTV—He injured the skin over the interphalangeal joint of his L thumb, which developedsurrounding erythema and a small pustule. It ruptured one week later.Mother put some antibiotic salve on it.

One week prior to presentation, he complained of his “face burning” and had pain under his arms, and requested a fan and cool cloths or ice packs on his face. He appeared fatigued but had no visible skin changes.

Two days later, his face was swollen and red, and he complained of pain when exposed to the sun.He developed an intensely pruritic, diffuse, micropapular, erythematous rash (scarlatiniform) on his chest, back, groin, buttocks, arms and legs. He was treated with TMP/SMX (Bactrim), orapred and hydroxyzine (Atarax). The pruritis worsened, and he developed skin peeling on his face, behind his ears, under his arms, and in his groin. He was admitted to an outside hospital, where the TMP/SMX was discontinued, and he was given IV vancomycin for 24 hours.He developed pain around his mouth and eyes that made it difficult to open his mouth and eyes completely.The desquamation on his face and under his arms worsened, and his story and pictures were sent to the St. Louis Children’s Hospital Diagnostic Center.He remained afebrile during the entire course, and maintained adequate enteral intake of solids and liquids.

ROS: He had one episode of dysuria, no hematuria, no wheezing or respiratory distress. No pain inside his mouth.

SH: He lives with his parents and two siblings.They have a pet dog.There is no recent travel. He had a tick attached on his right thigh about a week ago.The small seed tick was removed but was not identified.

FH: No history of skin infections or boils, blistering or photosensitivity. No hospital, prison or medical lab workers.

PE:(In the D.C.) Weight 21.3 kg (95th centile), height 116.5 cm (99th centile), BMI 15.7 (50th centile). BP 110/60.
Skin: His face had diffuse desquamation and a small amount of crusting around the corners of his mouth.He had crusting lesions with a small amount of erythema behind his ears. Dry, scaly skin under his arms, scattered areas of peeling skin on his chest with small red scabs, a small amount of desquamation in the periurethral area. Scab on dorsum of right thumb with mild surrounding erythema and desquamation.

HEENT:Conjunctiva clear. Oropharynx pink with no lesions on his tongue, buccal mucosa or soft palate. Neck: Shotty submandibular lymphadenopathy.Lungs:Clear to auscultation bilaterally.Heart: 2/6 systolic murmur at the left upper sternal border radiating to the right upper sternal border and left lower sternal border. The remainder of the exam was normal.

Lab:
WBC: 8.2 Hbg12.1. Plts297 56N, 31L, 11M
UA: 1.006, pH 7.0, negative
ESR: 5
Crp: <0.012 mg/dL
CMP: normal
Rapid strep: neg
Lyme antibody screen: negative
ASO titer 200 (<200 IU/mL)

Blood culture: negative

Course: The patient was given enteral clindamycin for an additional five days.

Dx: 1. Staphylococcal Scalded Skin Syndrome (SSSS)

Discussion:The progression of skin sensitivity, followed by edema, diffuse erythema, scarlatiniform rash and then superficial blistering is characteristic of Staphylococcal Scalded Skin Syndrome (SSSS). The desquamation usually occurs within 2-3 days of the onset of the rash in contrast to later desquamation in Kawasaki D., scarlet fever, toxic shock syndrome and rubeola. It can be clinically distinguished from Stevens-Johnson Syndrome (SJS) by the lack of mucous membrane involvement. As in this patient, SSSS is often preceded by a relatively minor staph aureus skin infection several days before the onset of systemic symptoms. Staphylococcal toxic shock syndrome (TSS) in prepubertal children also follows a trivial local infection and causes a diffuse sunburn-like rash. The desquamation is usually 1-2 weeks after onset of rash in survivors.

Most cases of SSSS are caused by methicillin sensitive staph aureus, although MRSA has been reported.¹ Depending on local prevalence and clinical severity, antibiotic coverage for MRSA may be indicated unless antibiotic sensitivities from a positive blood culture are available. The desquamation in SSSS can be severe enough to require admission to an intensive care or burn unit. CRP levels are often low, and elevations in CRP may suggest a secondary infection.²

The mechanism of blistering in SSSS is the same as in bullous impetigo, which it looks like in localized areas, but SSSS is generalized.It is a sloughing of the superficial epidermis, just below the stratum corneum. It is caused by breakdown ofdesmosomes, protein complexes that mediate intercellular attachment. The attachment in desmosomes is mediated by proteins called desmogleins and desmocollins. Staph can produce three exfoliative toxins (ETA, ETB and ETD), which are glutamate-specific serine proteases that cleave a single peptide bond in the extracellular region of desmoglein 1.³This leads to disruptions of the desmosomes where desmoglein 1 is the predominant form. In lower layers of the epidermis and mucous membranes, sufficient amounts of desmoglein 3 are present, and these tissues remain intact.Pathologic specimens from SJS show a subepidermal split with full-thickness epidermal necrosis.

Although toxic shock syndrome (TSS) also is caused by staph aureus, it is the result of adifferent exotoxin, toxic shock syndrome toxin-1 (TSST-1). TSST-1 functions as a superantigen by binding directly to an invariant region of class II MHC, inducing massive release of pro-inflammatory cytokines (4). TSS is characterized clinically by fever, hypotension and multi-system organ dysfunction. It also features diffuse macular erythroderma that gives way to desquamation, typically of the palms and soles, late in the illness.⁵

The autoimmune disease pemphigus foliaceus is caused by antibodies that attack desmoglein 1, and thus has a very similar clinical appearance to SSSS. In contrast, the autoimmune disease pemphigus vulgaris, is caused by antibodies that attack desmoglein 3, resulting in disruption of deeper layers of the epidermis and mucous membranes.⁶

Sources:

1. Neylon O, O'Connell NH, Slevin B et l. Neonatal staphylococcal scalded skin syndrome: clinical and outbreak containment review. Eur J Pediatr. 2010 Jul 13.
2. Blyth M, Estela C, Young AE. Severe staphylococcal scalded skin syndrome in children. Burns. 2008 Feb;34(1):98-103.
3. Nishifuji K, Sugai M, Amagai M. Staphylococcal exfoliative toxins: "molecular scissors" of bacteria that attack the cutaneous defense barrier in mammals. J Dermatol Sci. 2008 Jan;49(1):21-31.
4. Schlievert PM. Role of superantigens in human disease. J Infect Dis 1993 May;167(5):997-1002
5. Chesney PJ; Davis JP; Purdy WK; et al. Clinical manifestations of toxic shock syndrome. JAMA 1981 Aug 14;246(7):741-8
6. Stanley JR, Amagai M. Pemphigus, bullous impetigo, and the staphylococcal scalded-skin syndrome. N Engl J Med. 2006 Oct 26;355(17):1800-10

And several books by Susan Bayliss and colleagues from Washington University and other centers.