The Emerging Zika Virus Threat: A Guide for Dermatologists

Abstract and Introduction

Abstract

We provide a guide for dermatologists to follow if they encounter patients with a rash and clinical history suspicious of Zika virus infection, including diagnostic testing and management options. We also provide an illustrative case report of a patient from Brazil who was diagnosed with Zika virus infection after presenting with a generalized pruritic rash. One of the most prominent symptoms of Zika virus infection is a cutaneous eruption. As such, it is especially necessary for dermatologists to understand this virus so that they may appropriately recognize this entity as a diagnostic consideration in the clinic. The rash associated with Zika virus infection is most commonly an erythematous maculopapular eruption that presents after an initial 3–4 days of fever, headache, and arthralgia or myalgia. The rash typically lasts for an average of 6 days, and can spread to involve any part of the body, including the face, torso, extremities, palms, and soles.

Introduction

The Zika virus is a flavivirus that is primarily transmitted to humans through the bite of Aedes mosquitoes.^[1] It is closely related to the dengue virus, yellow fever virus, West Nile virus, and the Japanese encephalitis virus.^[2] The Zika virus was first discovered in Uganda in 1947, and over the next few decades, only sporadic cases of human infections were reported.^[2] In 2007, Zika virus presented as an outbreak for the first time outside its known endemic boundaries and caused an epidemic on Yap Island in the Federated States of Micronesia,^[3] and then another epidemic in 2013 in French Polynesia.^[4]

The recent outbreak of Zika virus in the Americas began in May 2015 in Brazil and has since spread to involve the USA, with over 3000 Zika virus cases reported in the USA as of September 2016, most of which were travel-related cases, except for the outbreak of cases identified in Florida.^[5] The rapid spread of this virus is alarming, as the Centers for Disease Control and Prevention (CDC) announced that the Zika virus is spreading faster than anticipated. It is particularly necessary for dermatologists to understand this virus so that they may appropriately recognize this entity as a diagnostic consideration.

Table 1. Clinical characteristics of similarly presenting febrile viral exanthems in travelers
	Zika	Chikungunya [53]	Dengue [54]	West Nile virus [55]
Severity	Majority asymptomatic (85%)	Majority symptomatic (70%)	Can cause asymptomatic (40–80%), mild, or serious illness	Majority asymptomatic (70–80%)
Illness course	Low-grade fever with headache and arthralgia or myalgia, followed by rash	Abrupt-onset fever, followed by debilitating arthralgia with associated symptoms	Initial abrupt-onset febrile phase, followed by critical phase and spontaneous recovery phase	Abrupt-onset fever, followed by associated symptoms
First symptoms/phase	Low-grade fever (<38.5 °C)	Sudden-onset high fever (>39°C)	Febrile phase: sudden-onset high fever (>39 °C); associated with headache, myalgia, retro-orbital pain, vomiting, macular rash, petechiae, and bruising	Sudden-onset fever
Second phase/other major symptoms	Headache, mild joint pain, pruritus, conjunctivitis, fatigue	Intense and debilitating symmetric polyarthralgia localized to large joints of arms and legs; occurs soon after onset of fever; in regions where chikungunya virus circulates, the debilitating polyarthralgia has a positive predictive value of >80%	Critical phase: systemic vascular leak syndrome occurs in small proportion of patients; persistent vomiting, increasingly severe abdominal pain, tender hepatomegaly, mucosal bleeding, lethargy	Headache, backache, myalgia, anorexia, rash, generalized lymphadenopathy, vomiting, diarrhea
Rash details	Maculopapular rash begins on torso or neck, spreads throughout body; typically occurs after initial 3–4 days of fever, arthralgia/myalgia; can be pruritic	Maculopapular rash occurs within 48 h of symptom onset; primarily on trunk; can appear on face, extremities, palms and soles	Transient macular rash and petechiae in initial febrile phase; second rash may appear during recovery phase, which varies from mild maculopapular exanthem to severe, pruritic lesions	Roseolar or maculopapular rash on face and trunk
Distinguishing features	Low fever	High fever, debilitating polyarthralgia	High fever, myalgia, headache	High fever, severe fatigue

Table 1. Clinical characteristics of similarly presenting febrile viral exanthems in travelers

Zika

Chikungunya [53]

Dengue [54]

West Nile virus [55]

Severity

Majority asymptomatic (85%)

Majority symptomatic (70%)

Can cause asymptomatic (40–80%), mild, or serious illness

Majority asymptomatic (70–80%)

Illness course

Low-grade fever with headache and arthralgia or myalgia, followed by rash

Abrupt-onset fever, followed by debilitating arthralgia with associated symptoms

Initial abrupt-onset febrile phase, followed by critical phase and spontaneous recovery phase

Abrupt-onset fever, followed by associated symptoms

First symptoms/phase

Low-grade fever (<38.5 °C)

Sudden-onset high fever (>39°C)

Febrile phase: sudden-onset high fever (>39 °C); associated with headache, myalgia, retro-orbital pain, vomiting, macular rash, petechiae, and bruising

Sudden-onset fever

Second phase/other major symptoms

Headache, mild joint pain, pruritus, conjunctivitis, fatigue

Intense and debilitating symmetric polyarthralgia localized to large joints of arms and legs; occurs soon after onset of fever; in regions where chikungunya virus circulates, the debilitating polyarthralgia has a positive predictive value of >80%

Critical phase: systemic vascular leak syndrome occurs in small proportion of patients; persistent vomiting, increasingly severe abdominal pain, tender hepatomegaly, mucosal bleeding, lethargy

Headache, backache, myalgia, anorexia, rash, generalized lymphadenopathy, vomiting, diarrhea

Rash details

Maculopapular rash begins on torso or neck, spreads throughout body; typically occurs after initial 3–4 days of fever, arthralgia/myalgia; can be pruritic

Maculopapular rash occurs within 48 h of symptom onset; primarily on trunk; can appear on face, extremities, palms and soles

Transient macular rash and petechiae in initial febrile phase; second rash may appear during recovery phase, which varies from mild maculopapular exanthem to severe, pruritic lesions

Roseolar or maculopapular rash on face and trunk

Distinguishing features

Low fever

High fever, debilitating polyarthralgia

High fever, myalgia, headache

High fever, severe fatigue