Case: headache, back pain, and fever
Answer
What diagnoses should top your differential?
Pyelonephritis, Genital herpes, herpes encephalitis
What additional tests should you order?
Urine culture and lumbar puncture with cerebral spinal fluid (CSF) , Herpes simplex virus polymerase chain reaction (PCR)
Where can you get to learn a brief tutorial on this topic?
The clinical presentation and urinalysis results could certainly be due to partially treat pyelonephritis, although bilateral pyelonephritis would be unlikely. You need to look for another explanation for vaginal symptoms and the headache with a positive jolt sign. She presumably has been treated for yeast, gonorrheas, and chalmydia, so the ongoing vaginal symptoms have to make you think of a mild case of gential herpes. She could also have mengititis due to herpes. The decision was made to proceed with a lumbar puncture for CSF examination. The lumbar puncture results were as follows: glucose normal at 80, protein elevated at 250, white blood cell count at 315 with a lymphocytic predominance. She was admitted, the herpes simplex virus PCR test later came back positive.
Discussion
Some of the most common mistakes in medicine department are made when the provider chooses a common diagnosis that does not quite fit, rather than looking deeper. In this case we do not have all the information from the urgent care clinic, but we can assume that the urine results suggested an infection. Urinalysis results does not infrequently lead providers astray by looking relatively benign in significant kidney infections and also by appearing positive when the actual causes of illness are elsewhere.
Genital herpes is a very common infection in US, with approximately 25% of the adult US population having antibodies to the virus from prior infection. Most of these people never outbreaks. Most clinicians can diagnose genital herpes when the presentation is typical, but in addition to silent cases, there are likely many sub clinical cases that present with only vaginal irritation, pain, such as this one, and these may be missed. For typical incubation, duration, and associated symptoms, and more see the table below.
Table: Genital Herpes
| Prevalence | 25% US IgG seroprevelance for HSV type 2, but must never have outbreaks |
| Clinical | painful vesciles that ulcerate: Genetial, buttock, sacral, thigh often recurs at same location May have nodes, fever headache can be mild: just irritation/discharge or asymptomatic |
| Timing | Incubation 2-20 days (typically-4 days) Duration 2-3 weeks |
| Comps | Keratitis , adrenal, liver, lungs |
| Tests | viral culture 95% sensitive if blister Tzanck smear: 50% sensitive, so rarely used any more Serology: IgM shows current/recent infection , IgG shows prior infection |
| Treatment | Acyclvoir: 400 mg PO TID * 10 days Valacyclvoir: 1000 mg BID*7 days (recurrence 500 mg BID*4 days) |
| contagion | Highest when lesion present, but asymptomatic shedding occurs ~25% of day |
Complications of herpes simplex infections are rare, but can include keratitis, encephalitis, involement of the adrenal glands, liver, or lungs. Complications are most common with a first outbreak and are not infruently missed on the first visit. Most complications require admission for IV acyclovir or speciality follow-up for isolated keratitis
