Author: Natalie Yapo MD, FAAP, Pediatric Emergency Medicine Fellow, University of Chicago

Author: S. Margaret Paik, MD, Associate Professor of Pediatrics, The University of Chicago, Comer Children’s Hospital, Chicago, IL

Editor: Matthew Tews, Medical College of Wisconsin

Last Update: 2015

Objectives     

1. Describe the general approach to describing rashes
2. Identify distinguishing features of common pediatric infectious rashes
3. Distinguish life-threatening rashes in children

Initial Assessment and Primary Survey

Rash is a common chief complaint for children in the emergency department. The general approach to the evaluation of rashes is to first identify whether the child is sick versus not sick. By going through the ABC’s as well as understanding age appropriate vital signs, the clinician should be able to identify children that are ill and may require a work up or a timely intervention.

In the initial evaluation, the child’s airway should be assessed. Urticaria may be associated with airway compromise such as stridor in the case of anaphylaxis. The child’s breathing should be assessed including the oxygen saturation and respiratory effort. When assessing the child’s circulation, the clinician needs to be aware whether the heart rate and blood pressure are age appropriate. The quality of central pulses (brachial, femoral, carotid) is also paramount in the circulation assessment.

When assessing the rash, describing the appearance, distribution and associated symptoms are paramount in figuring out the etiology of the rash. Below is a table that outlines the descriptions of rashes.

Rash Description

Flat lesions   No elevation or depression of skin	Description
Macule	<1cm
Patch	>1 cm
Elevated Solid lesion
Papule	< 0.5cm
Nodule	> 0.5cm
Plaque	>1cm
Fluid filled lesions
Vesicle	< 0.5cm
Bullae	> 0.5cm
Depressed lesions
Erosion	Extends into epidermis
Ulcers	Extends beyond epidermis

Figures from Wikimedia.org

Differential Diagnosis

Infectious Rashes in Ill Appearing Child

Meningococcemia

Meningococcemia, which is due to Neisseria meningitides, will often present in an ill appearing patient. Children less than 12 months are at the highest risk of meningococcemia.   Apart from fever, irritability and meningitis signs and symptoms, 2/3 of those affected will have a cutaneous manifestation. Early on the rash may appear morbilliform or urticarial macules and papules that often progress to petechial, pustules and vesicles. Late cutaneous features will include purpuric (non-blanching) lesions with jagged edges. Confirmatory tests include culture of the blood and CSF.

Purpuric rash 
Pictures from Wikimedia.org

Staphylococcal Scalded Skin Syndrome (SSSS)

SSSS is a toxin mediated rash produced by Staphylococcus aureus.  Children less than 5 years are usually affected and present with a generalized tender erythroderma and flaccid bullae. SSSS is typically associated with a positive Nikolsky sign, rubbing of the skin that causes skin desquamation or creates abullae within minutes.  The mucous membranes are often spared. Diagnosis is largely a clinical diagnosis as the bullae are sterile.

SSSS
Picture A: note the flaccid bullae
Picture B: erythroderma with bullae
Pictures courtesy of Dr. S Margaret Paik

Herpes Simplex Infection

Herpes Simplex Viral (HSV) Infection can cause localized or widespread infection. The classic rash associated with HSV is a painful vesicular (1-2 mm) and/ or ulcerative rash on an erythematous base. HSV-1 infection typically causes a localized infection of the mouth (herpetic gingivostomatitis), lips and/or eyes.  HSV-2 infection is commonly associated with genital infections and typically transmitted through sexual contact.

A child with herpetic gingivostomatitis usually has a fever accompanied by a vesicular and/or ulcerative rash of the buccal mucosa, tongue, gingivae, and perioral skin.  This differs from herpangina, which commonly appears on the soft palate, tonsillar pillars, uvula and posterior pharynx (see below for description).

If an HSV rash is located on the digits, it is referred to as a herpetic whitlow. In a child with atopic dermatitis with an overlying herpetic rash is referred to as eczema herpeticum .

Usually treatment options with acyclovir, valacyclovir or famciclovir are most efficacious when given within 48 hours of symptoms. Those with lesions proximal to the eyes should be urgently evaluated by ophthalmology . Those that appear ill, infants < 6 weeks old, signs of central disease (seizures, lethargy, altered mental status), immunocompromised, or widespread eczema herpeticum should be admitted for parenteral therapy.

Herpetic Gingivostomatitis
Picture A: note ulcers below two bottom teeth
Picture B: herpetic lesions on gingiva
Pictures from Wikimedia.org

Herpetic Conjunctivitis 
Note the vesicular lesions accompanied with conjunctival injection and
eyelid swelling (blepharitis).
Picture courtesy of Dr. S Margaret Paik

Eczema Herpeticum
Note the eczema of arms and face with small ulcerative rash on an erythematous base around mouth
Picture courtesy of Dr. S Margaret Paik

Non-Infectious Rashes in Ill Appearing Child

Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)

SJS and TEN are characterized by cutaneous and mucous membrane epidermal disruption. 

In Stevens Johnson Syndrome (SJS), the rash is preceded by  prodromal symptoms of fever, malaise, headache, sore throat for 1-14 days. The rash is described as target lesions which are erythematous concentric lesions with central duskiness that may turn into a blister and/or erosion. The rash commonly involves the palms and soles and <10% of the body surface area is involved in SJS.  The hallmark of SJS is the association of a characteristic rash with the involvement of >2 mucosal sites, i.e. oral, conjunctiva, urethral, esophageal.  Universally, hemorrhagic crusting of the lips and oral cavity are seen with SJS. The etiology of SJS may be drug related  (ie: anti-epileptics, NSAIDS, sulfonamides, acetaminophen) or infectious (ie: HSV, mycoplasma, EBV) or.  Treatment is largely supportive care and discontinuing offending drug agents.

SJS
Picture A: Target lesion, note central duskiness
Picture B and C: Examples of mucosal involment of  oral cavity 
and conjunctiva respectively 
Pictures from Wikimedia.org

Toxic Epidermal Necrolysis (TEN) is a severe form of SJS in that greater than 30% of the body surface area is involved. TEN is associated with multiorgan failure, >2 mucosal site involvement and rash characterized by widespread bullae eruption leading to epidermal sloughing. Usually those with TEN will need to be transferred to a burn unit and received intensive care monitoring.

TEN
Note widespread bullae 
Pictures from Wikimedia.org

Urticaria associated with anaphylaxis

Urticaria is described as pink to erythematous wheals that are pruritic and vary in shape and size. By definition, an urticarial lesion should change in its morphology or resolve within 24 hours. Acute urticaria (<6 weeks of duration) is typically benign. However when a child is experiencing anaphylaxis, an urticarial rash is the typical cutaneous manifestation.  Anaphylaxis is a potentially fatal disease that occurs after exposure to an allergen and causes a massive release of histamines, prostaglandins, and leukotrienes. Diagnosis is largely clinical and consists of the development of signs/symptoms within minutes to hours after an exposure. Such signs/symptoms include hypotension, cutaneous manifestations (urticaria, angioedema), respiratory signs (stridor, wheezing), and persistent gastrointestinal symptoms (emesis, abdominal pain). Treatment of urticaria can include oral anti-histamines such as diphenhydramine or .  Newer generation H1 blockers such as loratadine and cetirizine may also be used as they have a less sedating profile. Systemic corticosteroids are usually reserved for severe disease and can be associated with a rebound flare upon cessation. The first-line treatment of anaphylaxis includes IM epinephrine. In addition, one should also consider systemic corticosteroids, diphenhydramine and H2 blockers such as or famotidine as second-line therapy for anaphylaxis.

Urticaria
Pictures from Wikimedia.org

Henoch-Schonlein Pupura (HSP)

HSP is a type of vasculitis of unknown etiology.  A child with HSP will typically have a non-thrombocytopenic palpable purpuric (non-blanching) rash in the dependent areas such as lowers extremities and buttocks.  However, the rash can also present in the upper extremities, thorax, and face.  The rash may also be urticarial wheals or a maculopapular rash. Other associated symptoms may be arthritis, arthralgia, edema, and abdominal pain. Intussusception can occur in 2-3% of patients and 20-50% of patients will have renal involvement ranging from microscopic hematuria to glomerulonephritis.  Evaluation of a child with HSP should include a urinalysis (UA) to assess for hematuria and proteinuria as well as checking a blood pressure to assess for hypertension. There is no specific treatment for the rash as it will self-resolve. NSAIDS can be given for arthralgia and arthritis.  Corticosteroids have been shown to ameliorate GI symptoms.

HSP 
Note purpura of buttock extending to thighs 
Pictures courtesy of Dr. S Margaret Paik

Infectious Rashes in Well Appearing Child

Scarlet Fever

Scarlet fever is the association of a toxin-mediated exanthem from group A beta hemolytic streptococcus and pharyngitis or a skin wound. The rash is known as scarlatina. Children 4-8 years of age are most affected and typically present with fever, pharyngitis, headache and a rash. The hallmark of scarlatina is a widespread erythematous pinpoint papules described as a sandpaper rash, the presence of petechiae in the axillary folds or antecubital fossa known as Pastia lines, prominent papillae of the tongue (strawberry tongue), red cheeks with circumoral pallor. Confirmatory tests include rapid strep throat culture and/or throat strep culture.

Scarlett Fever
A. Example of strawberry tongue 
B. Note red cheeks with perioral pallor 
C. Erythematous papules “Sandpapery Rash”
D. Pastia lines in antecubital fossa
Pictures A,B, C from Wikimedia.org
Picture D courtesy of Dr. Natalie Yapo

Tinea Corporus/ Tinea Capitus

Tinea capitus is an infection of the scalp caused by a dermatophyte.  The infection may have different characteristics depending on the type of dermatophyte infection. The infection may result in circular patches of alopecia and scaling. Black dots may be seen due to remaining hair remnants in the follicle.  The infection may resemble seborrheic dermatitis (dandruff) in that there are patchy white to gray scaling with minimal alopecia. An inflamed tinea capitus lesion referred to as a kerion will present with a tender, erythematous boggy mass. Tinea capitus is often associated with suboccipital or posterior cervical lymphadenopathy. Typically this infection is clinically diagnosed but the gold standard for diagnosis is a fungal culture of a scale or hair fragment. Treatment of tinea capitus is an oral antifungal such as griseofulvin for 6-8 weeks.  Terbinafine is often used for refractory cases. An antifungal shampoo should also be used twice a week to decrease spread of infection.  Oral steroids should be considered as an adjunctive therapy for the treatment of a kerion.

Picture A: Tinea capitus-note the patch of alopecia with black dots
Picture B: Kerion- note the boggy erythematous appearance with associated alopecia
Pictures from Wikimedia.org

Tinea corporis is a cutaneous infection caused by a dermatophyte and causes annular lesions with a raised erythematous border and central clearing with associated scaling. A topical antifungal imidazole cream or ointment such as clotrimazole or topical allylamine such as terbinafine can used for treatment. Oral agents are reserved for extensive disease.

Tinea corporis-note the erythematous raised border with central clearing. 
Pictures from Wikimedia.org

Viral Exanthum

Viral exanthems are typically erythematous macules and papules in a child with a prodrome of upper respiratory infection symptoms, fever, and/ or gastrointestinal symptoms. The majority of viral exanthems will be non-specific for a particular virus. There are a few viruses that have a classic rash description as well as commonly associated signs and symptoms.  Erythema infectiosum or fifth disease due to Parvovirus B19 may cause a “slapped cheek” appearance with a lacy reticular rash. Roseola infantum also known as exanthem subitum typically occurs in children 6 months to 3 years of age and is characterized by 3-5 days of high fevers followed by a macular papular rash that occurs after the fever subsides.

Erythema infectiosum: note the bright red cheeks or “slapped cheeks” 
Pictures from Wikimedia.org

 
Hand Foot and Mouth Disease (HFMD)

HFMD is a viral exanthem most often caused by group A and B coxsackieviruses and enterovirus 71 in the late summer and early fall. Typically the child will be febrile with URI symptoms. The hallmark exanthem noted with HFMD are vesicles and small shallow ulcerations on an erythematous base in the oral cavity, palms and soles. Oral lesions will be located on the uvula, palate, tonsillar pillars, buccal mucosa, and tongue and can be painful. Apart from the palms and soles, other cutaneous lesions may occur around the mouth, buttocks, perineum, elbows, knees, and lateral aspects of the hands and feet.  If the child only has oral involvement, the rash is termed herpangina.  Diagnosis is made clinically. Treatment includes supportive care, analgesics for pain, antipyretics, and oral rehydration. In certain cases, the oral painful lesions may lead to dehydration requiring intravenous hydration.

Picture A: HFMD rash of the feet
Picture B: Perioral HFMD rash
Pictures from Wikimedia.org

Non-infectious rashes in well appearing child

Erythema Toxicum

Erythema Toxicum is a benign rash of unknown etiology that occurs in 50% of full term newborns. Typically the rash will erupt 24-48 hours after birth and may last up to 7 days. The rash is described as erythematous blotchy patches with an associated papule, pustule or vesicle. The rash typically spares the palms and soles. Diagnosis is largely made clinically. A Wright stain of the vesicle or pustule’s fluid will reveal largely eosinophils. No treatment is needed other than reassurance.

Transient Neonatal Pustular Melanosis

Transient Neonatal Pustular Melanosis may affect up to 5% of African American/ black infants. At birth, pustules are noted in various areas of the body including the palms and soles. Ruptured pustules will leave a hyperpigmented macule often with a scaly rim. Diagnosis is largely made clinically. A Wright stain of the pustule’s fluid will reveal largely neutrophils. No treatment is needed other than reassurance. The pustules will typically resolve in several days whereas the hyperpigmented macules will subside in 3-4 months.

Pityriasis Rosea

Pityriasis Rosea is a papulosquamous (papules and scales or scaly papules and plaques) rash that is self-limited. A herald’s patch is the initial lesion seen in 80% of patients and will have similar features of tinea corporis in that it is an oval or circular erythematous patch with central clearing and a scaly rim.  Within 2-4 weeks, the heralds patch will be followed by an eruption of erythematous papules and oval plaques with scales typically located on the torso. On the back, the rash has a “Christmas tree” distribution, refer to picture. The oval plaques long axis will be parallel to the lines of skin stress. Of note, in children with a darker complexion pityriasis rosea will have different features.  The rash may be more papular with few plaques as well as there may be an inverse distribution of the rash involving the neck, proximal extremities, groin and axillae rather than the torso. The rash may be pruritic. There is no specific treatment.  Exposure to sunlight may hasten the resolution of the rash

Pityriasis Rosea
Picture A: Herald’s patch-note erythematous patch with central clearing
Picture B: “Christmas tree” distribution of erythematous plaques
Pictures from Wikimedia.org

Pityriasis Rosea In African American Child
Note scaly papules and plaques 
Pictures courtesy of Dr. S Margaret Paik 

Pearls and Pitfalls:

• The appearance, distribution and associated symptoms are paramount in figuring out the etiology of a rash
• Recognizing an ill-appearing versus a well-appearing child is paramount when considering a life-threatening rash.
• Rashes that are life-threatening such as meningococcemia, TEN, SJS, herpetic lesions involving the eye, widespread eczema herpeticum, urticarial rash with anaphylaxis require timely recognition and intervention
• Urticaria with no other associated symptoms or signs is often benign and requires symptomatic care
• When urticaria is associated with hypotension, persistent GI symptoms, and/or respiratory signs a diagnosis of anaphylaxis should be considered
• Children with suspected HSP should be screened for renal involvement with a urinalysis, serum renal function determination and blood pressure monitoring
• Tinea corporis can be treated by a topical antifungal whereas tinea capitis is treated by an oral antifungal
• Viral exanthems are typically non-specific and usually require supportive care

References

1. Campbell RL, Li JT, Nicklas RA et al. “Emergency Department Diagnosis and Treatment of Anaphylaxis: a Practice Parameter”. Ann Allergy Asthma Immunology 113 (2014) 599-608.Print.
2. Kane, Kay Shou. Color Atlas & Synopsis of Pediatric Dermatology. New York: McGaw-Hill Medical, 2009. Print.
3. Krowchuk, Daniel P and Anthony J. Mancini. Pediatric Dermatology: A Quick Reference Guide. 2nd Elk Grove Village, IL: Section of Dermatology AAP Section of Dermatology, American Academy of Pediatrics, 2012. Print.
4. Lanzkowsky S, Lanzkowsky L., “Henoch-Schoenlein Purpura”. Pediatrics in Review. 13 (1992) 130-137. Print
5. Weston, William L. and Alfred T. Lane. Color Textbook of Pediatric Dermatology. 1st St. Louis, MO: Mosby Year Book,1991. Print.