Viral exanthems of childhood: Pathology review

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Viral exanthems of childhood: Pathology review


Pigmented skin disorders



Acneiform skin disorders

Acne vulgaris



Hidradenitis suppurativa

Papulosquamous and inflammatory skin disorders

Contact dermatitis

Atopic dermatitis

Lichen planus

Pityriasis rosea


Seborrhoeic dermatitis


Keratotic skin disorders

Actinic keratosis

Vesiculobullous skin disorders

Epidermolysis bullosa

Bullous pemphigoid

Pemphigus vulgaris

Desquamating skin disorders

Erythema multiforme

Stevens-Johnson syndrome

Skin integrity disorders

Pressure ulcer




Skin infections




Necrotizing fasciitis

Human papillomavirus

Varicella zoster virus

Poxvirus (Smallpox and Molluscum contagiosum)


Herpes simplex virus


Malassezia (Tinea versicolor and Seborrhoeic dermatitis)

Pediculus humanus and Phthirus pubis (Lice)

Sarcoptes scabiei (Scabies)

Human herpesvirus 6 (Roseola)

Parvovirus B19

Varicella zoster virus

Measles virus

Rubella virus

Skin neoplasms

Vascular tumors

Human herpesvirus 8 (Kaposi sarcoma)


Skin cancer

Hair and nail disorders

Alopecia areata

Telogen effluvium


Integumentary system pathology review

Pigmentation skin disorders: Pathology review

Acneiform skin disorders: Pathology review

Papulosquamous and inflammatory skin disorders: Pathology review

Vesiculobullous and desquamating skin disorders: Pathology review

Bacterial and viral skin infections: Pathology review

Skin cancer: Pathology review

Viral exanthems of childhood: Pathology review


Viral exanthems of childhood: Pathology review

USMLE® Step 1 questions

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USMLE® Step 1 style questions USMLE

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A 3-year-old boy is brought to the office by his parents due to a facial rash. The parents report the patient has been having a runny nose, diarrhea, and a fever of up to 38.3 ºC (100.9 ºF), for the past three days. Today, the patient developed a rash on his face, shown below. Laboratory evaluation is significant for a hemoglobin of 9 g/dL and a leukocyte count of 3000 cells/mm3. Which of the following best describes this patient's characteristics of the causative organism?
 Reproduced from ">Wikimedia Commons  


Content Reviewers

Antonella Melani, MD


Cassidy Dermott

Jake Ryan

Abbey Richard, BFA

A 1 year old boy named Adam is brought to the pediatric clinic by his mother, who is concerned because Adam developed a pink skin rash that began in the trunk and has now spread to the extremities.

On physical examination, the rash appears to be maculopapular. Upon further questioning, she recalls that Adam had a high fever for the past few days, and the rash appeared after the fever went down.

Next you see Rose, a 9 year old girl who came in with her father, due to a very itchy rash all over her body. Her father claims that the rash started 2 days ago after having a mild fever, and that several of Rose’s schoolmates also have the same rash.

Upon physical examination, you notice that the rash involves her face, trunk, and extremities, and presents with different types of lesions, including papules, vesicles, and crusts.

Now, based on the initial presentation, both Adam and Rose seem to have a viral exanthem of childhood, which is a group of eruptive skin rashes caused by viral infection and usually affect children.

Generally, viral exanthems can be macular, papular, maculopapular, or vesicular. A macular rash has macules, which are up to 5 mm in diameter, and completely flat, meaning that you can’t feel them if you run your finger over them.

On the other hand, a papular rash has papules, which are raised bumps that are up to 1 cm in diameter. And a maculopapular has both macules and papules.

Finally, a vesicular rash has vesicles, which are up to 5 mm in diameter, and look like clear blisters filled with fluid. Viral exanthems of childhood include varicella; hand-foot-mouth disease; roseola infantum; measles; rubella; and erythema infectiosum.

Alright, now one of the most common viral exanthems is varicella, more commonly referred to as chickenpox. It is caused by the varicella-zoster virus, or VZV for short, which is a DNA virus, and is also known as human herpesvirus 3 or HHV-3, as it belongs to the Herpesviridae family.

Now, this is a highly contagious airborne virus, meaning it’s transmitted from person to person through respiratory droplets; for example, when an infected person sneezes or coughs.


Viral exanthems of childhood are skin rashes that often affect children, and include varicella, hand-foot-mouth disease, roseola infantum, measles, rubella, and erythema infectiosum. Each has distinct symptoms and is caused by a different virus.

Varicella or chickenpox is caused by the varicella-zoster virus. It causes flu-like symptoms and a vesicular rash that spreads to the extremities and face. Measles caused by the measles virus leads to a high fever and a maculopapular rash that spreads in a cephalocaudal progression. There is also rubella caused by the rubella virus, which leads to flu-like symptoms and a maculopapular rash that spreads cephalocaudally, and can be transmitted by a pregnant individual to the fetus via the placenta.

Next is Hand-foot-mouth disease caused by the virus Coxsackievirus group A, which results in flu-like symptoms followed by a vesicular rash that begins in the mouth. Roseola infantum, which is human herpesvirus 6, presents with a high fever and a rose-colored maculopapular rash. There is also Erythema infectiosum caused by parvovirus B19, which presents with flu-like symptoms and a characteristic "slapped-cheek" rash, and can cause anemia in individuals with certain blood disorders or fetal anemia if contracted during pregnancy.


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  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "The varicella zoster virus vasculopathies: Clinical, CSF, imaging, and virologic features" Neurology (2008)
  6. "Coxsackievirus A6 and Hand,Foot and Mouth Disease:Three Case Reports of FamilialChild-to-Immunocompetent Adult Transmission and a Literature Review" Case Reports in Dermatology (2013)
  7. "Human Herpesvirus 6" Clinical Infectious Diseases (2001)

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