1. Assessing Rash Characteristics
Carrie A. Thomas, PhD
Epidemiologist (VPD/IBD)
Division of Infectious Disease Epidemiology
West Virginia Bureau for Public Health
(304)
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

2. Objectives
Describe features you should assess when investigating a report of a febrile rash illness
Review accompanying signs and symptoms associated with febrile rash illnesses
Define commonly used medical terms related to febrile rash illnesses
As public health employees, we often do not get to see patients face-to-face so it can be difficult to get an accurate description of the appearance of a rash when we are investigating febrile rash illnesses. We must get the patient or physician to verbally describe the appearance of the rash so we can help determine whether or not it fits a suspected diagnosis. So I’m going to spend the next 15 minutes or so describing the features you should assess when investigating a report of a febrile rash illness.
I’m also going to review some of the accompanying signs and symptoms you need to assess and define some commonly used medical terms you may hear concerning febrile rash illnesses
I’d like to point out that the characteristics we’re going to discuss are relevant to any rash presentation, but I’m going to focus on how to describe rashes associated with febrile rash illnesses.
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

3. Distribution Where is the rash located?
Localized – restricted to one area of the body
Generalized – present on several areas of the body
The first thing you want to know is where on the body a rash is located
Rashes can be localized or generalized.
A localized rash is restricted to one area of the body, while a generalized rash is spread out over the body
When assessing location, you may want to know whether or not the rash is located on the exposed parts of the body or whether it’s located on “high contact areas” where
Can anyone tell me what caused the rash in these pictures?
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

4. Distribution Where is the rash located?
Localized – restricted to one area of the body
Generalized – present on several areas of the body
Localized rash – Lyme Disease
Generalized rash – Rubella
Picture on left is typical bull's-eye rash associated with Lyme disease
Picture on left shows the generalized rash associated with rubella aka German measles
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

5. Progression
Did the rash move over the body during the course of illness?
Smallpox on first day of skin rash onset
You also want to know where the rash started and whether or not the rash moved over the body during the course of illness, so you need to know whether the progression of the rash can be tracked, or if it appeared in multiple areas simultaneously. If the rash progression can be tracked, you want to identify how it spread
did it start on the face and move down the body like a measles or rubella rash would
did it start on the torso and move outward, which would be a typical pattern to see in a chickenpox infection
did it start on the feet or legs and move up the body, or start in the peripherals and move toward the torso
This photo here was taken on the first day of skin rash onset in a patient with smallpox. This rash tends to start on the face, spreads to the arms and legs and then to the hands and feet, similar to the rash presentation for measles or rubella. I wouldn’t have included smallpox in this talk, but I couldn’t find and non-copywrited pictures showing rash progression for measles or rubella
Photographed on first day of skin rash onset. A rash emerges first as small red spots on the tongue and in the mouth. These spots develop into sores that break open and spread large amounts of the virus into the mouth and throat. At this time, the person becomes most contagious. Around the time the sores in the mouth break down, a rash appears on the skin, starting on the face and spreading to the arms and legs and then to the hands and feet. Usually the rash spreads to all parts of the body within 24 hours. As the rash appears, the fever usually falls and the person may start to feel better. By the third day of the rash, the rash becomes raised bumps. By the fourth day, the bumps fill with a thick, opaque fluid and often have a depression in the center that looks like a “bellybutton”, which is a major distinguishing characteristic of smallpox. Fever often will rise again at this time and remain high until scabs form over the bumps.
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

6. Color What color is the rash? Is the color uniform or patchy/blotchy?
Rashes can appear red, white, purple or silver
Is the color uniform or patchy/blotchy?
There are several things you want to consider when assessing the color of a rash.
Rashes can appear red, white, purple or silvery in color and you want to ask whether the rash has a uniform appearance or if there are darker and lighter patches within the rash
And some rashes will change during the course of the illness, so you want to know things like
Whether or not the rash changes color when you apply pressure
If the rash changed color over the course of the disease
Whether or not the rash is exacerbated by warm showers or increased physical activity
Any guesses for photos?
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

7. Color What color is the rash? Is the color uniform or patchy/blotchy?
Rashes can appear red, white, purple or silver
Is the color uniform or patchy/blotchy?
The photo on the left shows a rash associated with meningococcal infection, you can see here it’s purple in color. Meningococcemia is the more dangerous and deadly of illnesses caused by Neisseria meningitidis. When Neisseria meningitidis bacteria enter the bloodstream and multiply, they damage the walls of the blood vessels and cause bleeding into the skin and organs.
The photo on the right shows a child with measles, and you can see that the rash is darker and more red in some places than in others.
Meningococcemia
Measles
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

8. Texture
Rashes can be flaky, scaly, bumpy or smooth and the texture of the bumps may range from fine to course and can be solid or fluid-filled
Rashes can also vary in texture. They can be flaky or scaly, bumpy or smooth, and the texture of the bumps may range from fine to course and can be solid or fluid-filled
The picture on the left shows a scarlet fever rash, which first appears as tiny red bumps on the chest and abdomen that may spread all over the body. It looks like a sunburn, but if you run your hand over the skin, it feels like a rough piece of sandpaper. Scarlet fever is a good example of a fine rash with solid bumps
Varicella-Zoster virus or chickenpox infection causes a more course rash, and depending on the severity of the illness, the bumps can range from being close together to being several inches apart. Now that more and more children are receiving chickenpox vaccine, we’re seeing a lot more atypical presentations of varicella. Some children have fewer than 50 spots on their entire body and these can resemble bug bites, but in this picture you can see the fluid-filled bumps from a chickenpox rash
Scarlet fever
Chickenpox
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

9. Additional details Record additional details about the rash
Is it itchy?
Is it sore?
Is it numb or tingly?
Is it scabbing or crusty?
If there’s fluid involved, what color?
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

10. Accompanying signs and symptoms
Ask about additional signs/symptoms (and their timing in relation to rash onset date)
Fever, highest recorded temperature
Cough
Conjunctivitis
Respiratory symptoms, including runny nose
Joint pain
Swollen lymph nodes
Fatigue
The most important thing to assess when you’re dealing with febrile rash illnesses is the presence or absence of additional signs and symptoms. You want to know if the patient also experienced
Fever, highest recorded temperature
Cough
Conjunctivitis
Respiratory symptoms, including runny nose
Joint pain
Swollen lymph nodes
Fatigue
And you want to collect information about the timing of these additional symptoms in relation to the rash onset
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

11. Case Study
Get a report from a school that they have an outbreak of a rash illness
What’s the first thing you want to know?
Distribution: Face, trunk, arms, buttocks, thighs
Progression: started on face and trunk, moved out towards limbs
Color: bright red patches on cheeks,
Texture: flat discolored area with very small bumps, no vesicles, lacy rash on body
Accompanying signs/symptoms: rash is itchy – about 25% of kids had a mild fever, 40% reported feeling tired, 30% reported headache in the week before rash onset
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

12. Case Study – Line List Patient Rash Description Distribution/Location
Progression
Color
Texture
S&S
Case 1
Rash on trunk and face
Started on face then body
Face – bright red; trunk – red
Rough
Fever, headache
Case 2
Face, body
Face then body
Face – dark red; body red
Face – bumpy
Runny nose, fever
Case 3
Trunk and extremities
Just saw it on trunk and extremities
Red, appears like a lace pattern
Smooth
Abdominal pain, fever, headache
Case 4
torso
Saw it on torso
Dark pink
Did not touch it
Nausea, vomiting, fever, URTI
Distribution: Face, trunk, arms, buttocks, thighs
Progression: started on face and trunk, moved out towards limbs
Color: bright red patches on cheeks,
Texture: flat discolored area with very small bumps, no vesicles, lacy rash on body
Accompanying signs/symptoms: rash is itchy – about 25% of kids had a mild fever, 40% reported feeling tired, 30% reported headache in the week before rash onset
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

13. Case Study
Get a report from a school that they have an outbreak of a rash illness
What’s the first thing you want to know?
Distribution: Face, trunk, arms, buttocks, thighs
Progression: started on face and trunk, moved out towards limbs
Color: bright red patches on cheeks, lacy rash on body
Texture: flat discolored area with very small bumps, no vesicles
Accompanying signs/symptoms: rash is itchy – about 25% of kids had a mild fever, 40% reported feeling tired, 30% reported headache in the week before rash onset
Can I give them this?
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology
Fifth Disease aka Parvovirus B19

14. Medical Terms
Papule - A small solid rounded bump rising from the skin (scarlet fever)
Vesicle - a small blister filled with fluid (Hand, Foot & Mouth Disease)
Macule - A small localized change in the color of skin that is neither raised (elevated) nor depressed (Rocky Mountain Spotted fever)
Pruritic – itchy
Erythematous – red
Petechiae - Pinpoint flat round red spots under the skin surface caused bleeding into the skin (do not turn pale with pressure)
Purpura - A hemorrhagic area in the skin. Early purpura is red and becomes darker, then purple, and brown-yellow as it fades. Does not blanch when touched.
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology

15. Summary Distribution / Location Progression Color Texture
Additional info about the rash presentation
Itchy, sore, numb, etc.
Accompanying signs and symptoms
Fever, cough, respiratory symptoms, etc.
In summary, there are six areas to explore when assessing rashes associated with febrile rash illnesses.
You want to know where the rash is located if and how it progressed during the course of illness. You want to know what color the rash is and how the color may or may not have changed. You want to know about the texture of the rash, as well as any additional information you can gather about the rash symptoms, and most importantly, you want to know about accompanying signs and symptoms and the timing of these symptoms in relation to the rash onset.
Office of Epidemiology and Prevention Services
Divisions of Infectious Disease Epidemiology