EVALUATING PATIENTS FOR SMALLPOX ACUTE, GENERALIZED VESICULAR OR PUSTULAR RASH ILLNESS PROTOCOL Chickenpox (varicella) (variola) Smallpox Patient with Acute, Generalized Vesicular or Pustular Rash Illness

Institute Airborne & Contact Precautions Alert Infection Control on Admission

Classic chickenpox lesions Typical chickenpox Typical smallpox Classic smallpox lesions rash distribution Low Risk Moderate Risk High Risk rash distribution of Smallpox of Smallpox of Smallpox (see “Risk of Smallpox” below) (see “Risk of Smallpox” below) (see “Risk of Smallpox” below) IMAGES OF CHICKENPOX (VARICELLA) IMAGES OF SMALLPOX ID and/or Derm Consultation ID and/or Derm Consultation History and Exam Alert Local and State Health Diagnosis Varicella +/- Departments Immediately Highly Suggestive Other Lab Testing as Indicated of Varicella Uncertain (contact information below)

Response Team Test for Non-Smallpox No Diagnosis Made Advises on Varicella Testing Varicella and Diagnosis Confirmed Ensure Adequacy of Specimen Management & Specimen Optional Other Conditions Report Results to ID/Derm Consultant Collection as Indicated Infection Control Re-Evaluates Patient Day 3 of rash Day 5 of rash Day 7 of rash

Cannot R/O Smallpox Testing Healthy child Healthy adult Bacterial superinfection Classify as High Risk at CDC with varicella with varicella of varicella lesions RISK OF SMALLPOX NOT Smallpox SMALLPOX High Risk of Smallpox → Report Immediately Further Testing 1. Febrile prodrome (defined below) AND 2. Classic smallpox lesion (defined below & photo at top right) AND Note centripetal Day 3 of rash Lesions are in different distribution of rash stages of development 3. Lesions in same stage of development (defined below) On any one part of the body, all lesions are in the same stage of development Umbilicated lesions (back of hand) Moderate Risk of Smallpox → Urgent Evaluation There have been no naturally occurring cases of smallpox anywhere in the world 1. Febrile prodrome (defined below) AND since 1977. A high risk case of smallpox is a public health and medical emergency. 2. One other MAJOR smallpox criterion (defined below) Report all HIGH RISK CASES immediately (without waiting for lab results) to: OR 1. Febrile prodrome (defined below) AND 1. Hospital Infection Control ______( ) ______- ______2. ≥4 MINOR smallpox criteria (defined below) ______( ) ______- ______Low Risk of Smallpox → Manage as Clinically Indicated 2. ______health department ( ) ______- ______( ) ______- ______1. No febrile prodrome Healthy adult Healthy adult Pregnant woman 3. ______health department ( ) ______- ______OR Most patients with smallpox have lesions on the palms or soles Confluent lesions with varicella with varicella with varicella 1. Febrile prodrome AND ( ) ______- ______2. <4 MINOR smallpox criteria (defined below) DIFFERENTIATING CHICKENPOX FROM SMALLPOX COMMON CONDITIONS THAT MIGHT BE CONFUSED WITH SMALLPOX

Chickenpox (varicella) is the most likely condition to be confused MAJOR SMALLPOX CRITERIA CONDITION CLINICAL CLUES with smallpox. ƒƒ FEBRILE PRODROME: occurring 1-4 days before rash onset: fever ≥101°F and at least one of the following: Varicella (primary infection with Most common in children <10 years; children usually do not have a viral varicella-zoster virus) prodrome In chickenpox: prostration, headache, backache, chills, vomiting or severe abdominal pain Immunocompromised or elderly persons; rash looks like varicella, ƒƒ CLASSIC SMALLPOX LESIONS: deep-seated, firm/hard, round well-circumscribed vesicles or pustules; as they Disseminated herpes zoster ƒƒ No or mild prodrome evolve, lesions may become umbilicated or confluent usually begins in dermatomal distribution ƒƒ Lesions are superficial vesicles: “dewdrop on a rose petal” (see photo at top) ƒƒ LESIONS IN SAME STAGE OF DEVELOPMENT: on any one part of the body (e.g., the face, or arm) all the lesions Impetigo (Streptococcus pyogenes, Honey-colored crusted plaques with bullae are classic but may begin as ƒƒ Lesions appear in crops: on any one part of the body there are lesions in are in the same stage of development (i.e., all are vesicles, or all are pustules) Staphylococcus aureus) vesicles; regional not disseminated rash; patients generally not ill different stages (papules, vesicles, crusts) Drug eruptions Exposure to medications; rash often generalized Itching; contact with possible allergens; rash often localized in pattern ƒƒ Centripetal distribution: greatest concentration of lesions on the MINOR SMALLPOX CRITERIA Contact dermatitis trunk, fewest lesions on distal extremities. May involve the face/scalp. suggesting external contact ƒƒ Centrifugal distribution: greatest concentration of lesions on face and distal extremities Target, “bull’s eye,” or iris lesions; often follows recurrent herpes simplex Occasionally entire body equally affected. Erythema multiforme minor ƒƒ First lesions on the oral mucosa/palate, face, or forearms virus infections; may involve hands & feet (including palms & soles) ƒƒ First lesions appear on the face or trunk ƒƒ Patient appears toxic or moribund Erythema multiforme (incl. Major form involves mucous membranes & conjunctivae; may be target ƒƒ Patients rarely toxic or moribund ƒƒ Slow evolution: lesions evolve from macules to papules → pustules over days (each stage lasts 1-2 days) Stevens-Johnson Syndrome) lesions or vesicles ƒƒ Rapid evolution: lesions evolve from macules → papules → vesicles → Summer & fall; fever & mild pharyngitis 1-2 days before rash onset; lesions ƒƒ Lesions on the palms and soles Enteroviral infection esp. Hand, initially maculopapular but evolve into whitish-grey tender, flat often oval crusts quickly (<24 hours) Foot and Mouth disease vesicles; peripheral distribution (hands, feet, mouth, or disseminated) ƒƒ Palms and soles rarely involved Disseminated herpes simplex Lesions indistinguishable from varicella; immunocompromised host ƒƒ Patient lacks reliable history of varicella or varicella vaccination Photo Credits: Dr. Thomas Mack, Dr. Barbara Watson, Dr. Scott A. Norton, Dr. Patrick Alguire, World Health Organization, American Academy of Pediatrics, American Academy of Dermatology Scabies; insect bites (incl. fleas) Itching is a major symptom; patient is not febrile & is otherwise well ƒƒ 50-80% recall an exposure to chickenpox or shingles 10-21 days before Molluscum contagiosum May disseminate in immunosuppressed persons rash onset

For more information, please go to the CDC website www.cdc.gov/smallpox

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