Mrs. X brought her 5-year-old son to the office with a rash. The nurse ushered them into a room and took his vitals. Before entering I grabbed the chart to review it. I was intrigued upon seeing the chief complaint to be possible shingles.

 

Mom explained, “I know I shouldn’t have done this, but I did a Google search. I think Billy has shingles.” About two weeks ago she had noticed a red rash on the back of his leg. It extended from the middle of his thigh to nearly mid-calf. It was red and slightly raised. He had no fever nor was it painful or itchy. Aside from the rash he seemed perfectly fine.

 

She showed me some pictures of shingles that she had on her phone.

 

I commended her for the detective work and acceded that shingles was a good thought. But the lack of pain or burning made the diagnosis less likely. My thought was that he had lichen striates. After showing her pictures from a dermatology textbook she exclaimed, “Oh my goodness, that’s EXACTLY what he has!”
 

Lichen stratus is an uncommon skin condition that can occur at any age.

 

It is primarily a childhood condition with over 50 percent of cases occurring between the ages of 5 and 15 years. It is two-to-three times more likely to occur in females than in males. It is a very benign condition that does not require any treatment and typically resolves over time. It is NOT contagious, so a child with lichen stratus should not be kept out of school.

 

Typically lichen stratus starts as a rash on the arm or leg and evolves over one-to-two weeks.

 

It begins as pink or red slightly raised, shiny spots that may coalesce into clumps of linear bands that extend down an arm or leg. The band is usually thin, two millimeters-to-an inch wide. It may be a few inches long or extend down the entire limb. The rash follows the Lines of Blaschko which are felt to be pathways of epidermal cell migration and proliferation during the embryological development of the fetus. These “lines” do not follow any nervous system or vascular system pathways. They never cross the midline. It is of interest merely because there are many inherited and acquired skin conditions that also follow the so-called Lines of Blaschko.
 

Lichen stratus does not cause any symptoms other than mild itchiness in some cases. Treatment is not required.

 

If there is some itchiness a mild topical steroid may give relief. The rash does not usually spread once it is present. It resolves anywhere from one month to a year. The average time of complete resolution is around six months. Upon resolving it may leave a pale or hypo-pigmented area where it was located. But this is typically subtle. In some cases there may be a residual darker or hyper-pigmented remnant. In both cases there should be complete resolution.

 

Less commonly, lichen stratus may involve the nail of a finger or toe.

 

This may cause the nail to become ridged, split, discolored or may actually fall off. This would involve only the nail and not the skin of the finger. This is quite rare with only 30 cases reported in the literature as of 2020. This, too, will completely resolve in time. However it may take well over a year. When it does resolve, a perfectly normal nail should grow back.

 

There is no known cause for lichen stratus although there are differing theories about how it occurs.

 

Some suggest that it represents an auto-immune skin condition mediated by T-cells. Other theories are that it is caused by environmental factors such as viruses (particularly post influenza or chicken pox) or trauma (post vaccination).