Chickenpox vs Hand Foot and Mouth | Causes, Clinical Features, Complications, Diagnosis, Management
 

The key difference between chickenpox and hand foot and mouth disease is that chickenpox is caused by a herpes virus while hand foot mouth disease is caused by a picorna virus.

Chickenpox and hand foot and mouth disease, both of which are caused by viral infections, share some common characteristics and causes diagnostic confusion. But several features of the two diseases are significantly different. This article points out the differences between chickenpox and hand foot mouth disease with regard to the organism responsible, clinical picture, complications, diagnosis, and management.

CONTENTS

1. Overview and Key Difference
2. What is a Chickenpox 
3. What is Hand Foot and Mouth Disease
4. Side by Side Comparison – Chickenpox and Hand Foot vs Mouth Disease in Tabular Form
5. Summary

What is Chickenpox?

Varicella zoster, which belongs to the herpes virus family, is responsible for this disease. It is a DNA virus and has the ability to cause latent infections. The disease transmission is by respiratory droplets and direct contact with the lesions. It is highly infectious and more severe in adults, pregnant women, and immune-compromised people. Immunity following the disease is lifelong.

Vesicular eruption begins following an incubation period of 14-21 days, often on the mucosal surfaces first and then rapid dissemination in a centripetal distribution mostly involving the trunk. The rash progresses from small pink macules to vesicles and pustules within 24 hours and then crust. Moreover, the lesions appear to be in different stages of development. The pocks are more superficial, and the vesicles collapse on puncture.

Figure 1: Varicella-zoster Virus

Furthermore, the lesions are itchy, and scratching can lead to secondary bacterial infection, which is the most common complication. Rare complications involve self-limiting cerebella ataxia, varicella pneumonia, encephalitis, and Reye’s syndrome, especially in children who are on aspirin.

Physicians make the clinical diagnosis by the classic appearance of the rash. In addition, aspiration of the vesicular fluid and PCR or tissue culture confirms the diagnosis.

Acyclovir is effective in the management of the disease, especially, if commenced within 48 hours of the rash. Moreover, live attenuated VZV is given for highly susceptible contacts.

Hand foot and mouth disease is a systemic infection caused by coxsackievirus A16, which belongs to the picornaviridae family. The disease is moderately infectious. Transmission of the disease is by direct contact with mucus, saliva or feces of an infected person. It mostly affects children and rarely adults.

Following an incubation period of 10 days, mild illness of fever and lymphadenopathy occur. After 2-3 days, a vesicular rash appears on palmoplantar surfaces of the hands and feet with associated mouth lesions that ulcerate rapidly. A papular erythematous rash may appear on buttocks and thigh, as well.

Figure 2: Coxsackievirus

Isolating the virus or observing a rise in titer of neutralizing antibodies help in making the diagnosis.

The disease is self-limiting and usually resolves within 2 weeks after the onset. In case if the lesions are painful, analgesics can be given. However, passive immunization is not recommended.

The complications of the disease are very rare and include mild viral meningitis, encephalitis, and paralysis.

Herpes virus causes chickenpox while a picorna virus causes hand foot and mouth disease. This is the key difference between chickenpox and hand foot and mouth disease. Moreover, the incubation period of chickenpox is 14-21 days, while the incubation period of hand foot and mouth disease is 10 days. In chickenpox, lesions appear mostly in the trunk, but in hand foot mouth disease, they appear on palmoplantar surfaces of the hands and feet, with associated mouth lesions that ulcerate rapidly. This is another important difference between chickenpox and hand foot and mouth disease.

Although chickenpox needs to be treated with acyclovir, hand foot mouth disease is self-limiting. Moreover, an effective vaccine is available against chickenpox, but there is no need for vaccines in hand foot mouth disease.  Finally, chickenpox is highly infectious, but hand foot mouth disease is moderately infectious. This is another major difference between chickenpox and hand foot and mouth disease.

Summary – Chickenpox vs Hand Foot and Mouth Disease

The key difference between chickenpox and hand foot and mouth disease is their viral origin;  herpes virus causes chickenpox while a picorna virus causes hand foot and mouth disease. There are other differences between the two diseases based on the clinical picture, complications, diagnosis, and management.

Image Courtesy:

1. “Varicella-zoster Virus” By NIAID (CC BY 2.0) via Flickr
2. “Coxsackie B4 virus” (Public Domain) via Commons Wikimedia

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