Lumbosacral HSV is a recurrent fever blister outbreak that appears on the lower back, upper buttocks, or nearby skin in the sacral nerve distribution. It is usually caused by reactivation of herpes simplex virus that has remained dormant in sensory nerve tissue, then becomes active again later. It is frequently misdiagnosed as recurrent shingles, but it is extremely uncommon to have shingles multiple times, while lumbosacral HSV recurs far more regularly.
What It Is
Lumbosacral HSV has been linked to both the fever blister virus that occurs on the lip and the type of HSV that is associated with genital herpes. However, this rash is not usually a new or recent infection, so don’t jump to accuse your long-term sexual partner of infidelity. Instead, it reflects reactivation of virus that has been latent in the nerve root or dorsal root ganglion for decades and then travels back to the skin.
Why It’s Missed
Lumbosacral HSV is often misdiagnosed as shingles because it can appear stripe-like on the back. It also shares symptoms with shingles, such as burning or tingling before the rash, clusters of small blisters, tenderness, and crusting as the area heals.
Common Triggers
Outbreaks may be linked to stress, recent illness, and changes that affect the immune system. While this may occur at any age, it seems to occur most often in people over 60, as the immune system doesn’t keep the virus in check as well as it used to.
Treatment Options
Lumbosacral HSV can be treated episodically, meaning antiviral medicine is started at the first sign of burning, tingling, or a new outbreak to shorten symptoms and healing time. CDC guidance for recurrent HSV states that episodic treatment works best when started within 1 day of lesion onset or during the prodrome.
If outbreaks happen multiple times a year, suppressive treatment with daily antiviral medication can reduce how often recurrences happen and can improve quality of life. CDC guidance states that suppressive therapy can reduce recurrence frequency by 70% to 80% in patients with frequent recurrences.
When to Seek Care
Seek medical care if the rash is severe, the diagnosis is unclear, outbreaks are frequent, pain is significant, or the lesions are not healing as expected. Also come in for a visit if you are pregnant.
Have questions about a recurring rash like this, or want me to take a look? You can book online or call the office at 423-528-8833. This page is for general education, not a substitute for a personal exam.