Skin rashes can reveal much information about infectious diseases

SAN FRANCISCO — Rocky Mountain spotted fever, meningococcal disease, staphylococcal toxic shock syndrome and streptococcal toxic shock syndrome are four infectious diseases with important skin manifestations that have significant rates of morbidity and mortality.

“These are truly dermatologic emergencies,” said Lisa A. Drage, MD, a consultant in the department of dermatology at the Mayo Clinic, Rochester, Minn.

The four diseases Drage discussed here at the 61st Annual Meeting of the American Academy of Dermatology have mortality rates ranging from 10% to 75%. In 2000, there were 2,256 reported cases of meningococcal disease. She said that is much higher than the 183 reported cases for streptococcal toxic shock syndrome. “This syndrome is probably significantly under-reported because it is not even a reportable disease in several states,” Drage said.

Rocky Mountain spotted fever

Despite its name, the state with the greatest number of cases of Rocky Mountain spotted fever (RMSF) is North Carolina. “The name itself is somewhat of a misnomer because it was first noted in the mountains of Montana,” Drage said. “But it is more common in the Southeast and Central regions of the country.”

Ticks — often a dog tick — carry the disease.

“Usually transmission occurs after six hours, so if you can remove the ticks quickly, you are less likely to have problems,” Drage said. The seasonal disease (spring and summer, when ticks are most active) afflicts people who spend lots of time outdoors. “The person most likely to present is a young boy who has a dog,” Drage said.

RMSF can be treated easily if observed early. “But if it is missed, it has a very high mortality rate,” Drage said. Along with fever and malaise, patients often have a very severe headache. “Many adult patients say it is the worst headache they have ever had,” she said. A rash typically begins on day four, then spreads to the wrists and ankles, palms and soles, and finally all over the body. “By not catching the rash right away, you are just going to see a generalized eruption,” Drage said. The macular eruption rapidly becomes petechial.

Current management for the disease involves doxycycline, tetracycline or similar antibiotics. “If there is a possibility of disease, it is probably best to start the patient on antibiotics. These drugs have a relatively low toxicity rate,” Drage said.

Signs of meningitis

Rash in patient whose spinal fluid and blood cultures grew Neisseria meningitidis

Source: dermatlas.org

Meningococcal disease is primarily considered a childhood disease. However, “at least one-third of cases are now in adults,” Drage said. And in 2000, “55% of reported cases were in adults. So this may be a new trend.”

Furthermore, roughly 10% to 20% of the general public carry the organism. “The number of carriers increases in a crowded situation,” Drage said. Living in college dormitories and military barracks, in particular, present a high carrier rate and the potential for outbreaks.

“Transmission is via droplet spread, not aerosolized particles,” Drage said. “This makes a big difference in who will acquire the disease.”

In a hospital, direct exposure to secretions is more likely to transmit disease. Meningococcal disease is also seasonal, peaking in early spring. “Despite all our diagnostic and therapeutic abilities, the disease still has a very high mortality rate,” Drage said.

Prompt diagnosis and treatment increases survival. “One of the hallmarks of the disease is the rapid, spiraling progression,” Drage said. “There are very dramatic accounts of college students going to bed with a rash and fever, but not waking up.” Most patients present with an extremely high fever, along with nausea, headache and/or vomiting. “Children are markedly lethargic. Parents will say it appears different from a normal viral illness,” Drage said.

But skin lesions are one of the significant clues in making a proper diagnosis, and one of the earliest signs. “A classic picture of meningococcemia disease consists of angulated borders and central gray areas of necrosis,” Drage said. However, some adults will present without a rash.

“Even if a patient has already received antibiotics, it is still worthwhile to obtain a skin biopsy for culture and looking for meningococcemia,” Drage said. In addition, newly developed polymerase chain reaction (PCR) tests are becoming more prevalent — for both diagnosis and typing. “With most isolates, penicillin G is still the best form of treatment,” Drage said. Prophylactic treatment is offered for close contact with possible secretion exposure, especially for all day care contacts.

Staph toxic shock syndrome

Staphylococcal toxic shock syndrome is more likely to be seen today in patients who are not menstruating, including men. “We’re seeing more cases after influenza, with different types of barrier contraceptives, wound infection and any sort of packing (such as nasal),” Drage said. Furthermore, the disease can recur in up to 40% of cases. “Often, the diagnosis is retrospective,” she said. In other words, “after people have shown up a few times with a hypotensive disorder that eventually indicates desquamation, the diagnosis is made,” Drage said. Diarrhea and mental confusion are often present as well.

Mucosal hyperemia can be an important clue in patients with dark skin. Strawberry tongue is also common in patients.

Management includes identification and removal of the source. Antistaphylococcal antibiotics are also key. “Different hospitals have different resistance patterns,” Drage said. Intravenous immune globulins (IVIGs) are used to neutralize circulating toxins. “Clindamycin is often added,” she said.

Strep toxic shock syndrome

Streptococcal toxic shock syndrome is also significantly associated with hypotension. “The disease is usually seen with an invasive soft-tissue infection — swelling or redness,” Drage said. A portal of entry (burn, laceration or wound site) is common. Healthy middle-aged people are most prone. “The mortality rate is still high,” Drage said. Clinical manifestations include fever and severe pain. “The pain is often on an extremity and disproportionate to the exam findings,” Drage said.

Broad-spectrum antibiotics are followed by more definitive treatment with penicillin G, clindamycin and IVIG. “These patients are usually extremely ill, so they also need supportive care too,” Drage said.

For more information:

• Drage LA. Killer rashes. Presented at the American Academy of Dermatology 61st Annual Meeting. March 21-26, 2003. San Francisco.