Question

A. The patient is a 23-year-old male who works as a baker's assistant. He presented to the local emergency room with low-grade fever, malaise, and headache. He was sent home with a diagnosis of influenza. He presented 7 days later with a 1-day history of worsened headache, photophobia, and stiff neck. On physical examination he appeared to be in mild distress with a temperature of 102.2 oF. He had mild nuchal rigidity and a maculopapular rash on his trunk, arms, palms, and soles. Areas on his palms and soles had some papulosquamous lesions. There were no mucous membrane lesions. No focal deficits were seen on neurologic examination.

He had a white blood cell count of 11,200/mm3 with an increased number of PMN. A computed tomogram (CT scan) of the head was normal, and a lumbar puncture revealed 120 white blood cells/mm3 with 80% lymphocytes and 20% PMN, a glucose level of 40 mg/dl (normal), and a protein level of 82 mg/dl (elevated).

Blood cultures were obtained, and antimicrobial therapy was begun. The next day a serologic test of his CSF and blood revealed the diagnosis. Further questioning of the patient when the serology results were known revealed that 1 month previously, he had a painless ulcer on his penis which healed spontaneously. His condition improved greatly over the next 3 days and his rash cleared within 10 days.

1. Which bacterial infections can cause a maculopapular rash? What is the most likely agent of his infection?

2. In what stage of this infection is this patient? What is the significance of his CSF findings? Describe the disease course as it occurs in infected patients who go untreated.

3. How can the diagnosis of this infection be made? What is the difference between the screening test for the organism infecting this patient and the confirmatory test? How are these two tests used?

4. If this patient had been found to have a T-helper cell count of <200 and was HIV seropositive, what adjustment to his antimicrobial therapy would be necessary to treat the infection causing his skin rash?

Answer 1

Maculopapular rashes may be present in many different conditions. Some may be due to:

• drug reactions
• bacterial or viral infections
• allergies
• our body’s own systemic inflammation

Drug reactions

Allergic reactions to a drug may be the cause if the maculopapular rash develops four to 12 days after taking a medication. Reactions to medications can take up to seven or eight days to show symptoms. You may experience a low-grade fever and muscle pain. The rash generally fades after one to two weeks.

Read more: Identifying and caring for an amoxicillin rash »

Infection

If a viral or bacterial infection is the cause of your rash, you will also experience other symptoms such as a fever, headache, muscle pain, and breathing troubles. Possible viral causes include:

• EBV infection
• measles
• scarlet fever
• hand, foot, and mouth disease
• herpes
• hepatitis B or C infection
• Zika
• Ebola
• HIV

Allergic reaction

A rash that breaks out immediately may also be due to allergies. This usually happens within minutes to hours of exposure to the allergen. Sometimes a maculopapular rash may break out before hives do. A person may also experience increased heart rate and breathing problems.

Body’s systemic inflammation

The body’s own systemic inflammation can cause maculopapular rashes. Inflammation is how your body responds to an injury or infection. A drug reaction, infection, an autoimmune response, or allergic reaction can cause your body’s immune system to respond and develop maculopapular rashes.

In addition, such rashes can occur in sexually-transmitted infections like secondary syphilis and condylomata.

Cerebrospinal fluid (CSF) is a biologic fluid, formed mainly in the ventricular choroid plexus, distributed within the ventricular system, basal cisterns, and subarachnoid space. Analysis of the CSF provides invaluable diagnostic information because diseases take place either within its bounding membranes (e.g., meningitis) or in the adjoining parameningeal structures of the brain (e.g., brain abscess).

What to do if you have a maculopapular rash

Fast facts

1. A maculopapular rash is when your skin erupts in flat or raised red bumps.
2. Viral infections are the most common cause, but only a doctor can help diagnose your condition.
3. Keep a record of when the rash developed, how it progressed, and other symptoms.
4. Follow the doctor’s instructions for recovery.

Use medications as prescribed, including antihistamines and skin creams. Follow the doctor’s instructions for recovery, and take care not to infect others if the cause of your rash is infectious.

Use insect repellant and take measures to eradicate mosquitoes in and around your neighborhood. Always follow up with your doctor if your rash is interfering with your day-to-day life.