he Case of Compound Follicles
“Compound follicles” are follicles with 6 or more hairs coming out of a single pore. Occasionally, follicles with 4,5 and rarely 6 hairs coming out of a single pore can be found as an isolated finding- especially towards the more posterior regions of the scalp. But large groupings of hairs like this are rare with advancing age and in fact – the presence of many areas containing compound follicles should prompt the clinician to consider that the patient might have a scarring alopecia. Compounding occurs when 2 or more adjacent follicles “fuse” together. They do not occur because a hair follicle suddenly makes more hairs. Compound follicles are more common in neutrophilic scarring alopecias like folliculitis decalvans (FD) than in lymphocytic scarring alopecias like lichen planopilaris (LPP). Nevertheless, occasional follicles with 5 and 6 hairs can be found in LPP…. as we’ll see in the case below.
I’ve included below a schematic diagram showing the typical findings in lichen planopilaris (LPP) and folliculitis decalvans (FD). Lichen planopilaris typically has no compounding although rarely it’s true that we can see it ….as we’ll seen in the case below. Compounding is more common in folliculitis decalvans.
Generally speaking, the tendency in LPP is for hairs to be destroyed and follicles to contain fewer and fewer hairs over time rather than to contain more follicles in them.
The case was a patient who presented with redness in the scalp and a loss of hair density. Trichosocpy of the scalp is shown in the photo above. The arrow points to a follicle with 6 hairs coming out of a single pore. There were not many other features in this photos that suggested LPP such as perifollicular scale or perifollicular erythema or pili torti or scarring.
Below is a more typical photo of lichen planoplaris. As you’ll likely agree, the above photo doesn’t quite look like the only below. The typical photo of LPP has scale around hairs. Furthermore, most of the hairs either come out of the pores in groups of 2 or just one hair or no hair at all !
Occasional hairs in our patient’s case had a thicker scale than expected in LPP which prompted me to also consider whether this could be “starburst” scaling of FD. A “hint” of crusting is present but there are no pustules. Redness is interfollicular. A typical trichoscopic image of FD is shown below:
A biopsy was be done to evaluate for the possibility of scarring alopecia. The biopsy returned showing lichen planopilaris with no features of folliculitis decalvans. The biopsy also showed that there was a perifollicular inflammatory infiltrate of lymphocytes together with lichenoid change (death of keratinocytes) in the outer root sheath. Perifollicular fibrosis was seen along with loss of sebaceous glands.
FINAL DIAGNOSIS: LICHEN PLANOPILARIS.
Comment on Case
This was a nice example of a case that was atypical. Not all patients with lichen planopilaris have a typical presentation. Most however have scalp symptoms (like itching or burning or tenderness). Most have redness of some sort in the scalp. Most of scale around hairs. This patient had a bit of subtle redness and not really that much in the way of symptoms. The patient had some unusual compounding by trichoscopy which was the tip off that something might not be right. The biopsy confirmed the diagnosis of lichen planopilaris. Compounding is not a typical feature of LPP but certainly can be seen from time to time. It’s usually not a feature seen in all regions of the scalp and usually the compounding is limited to less than 7 hairs. Compound hairs containing 10, 15 our 20 hairs are almost never seen in lichen planopilaris (LPP) but can be seen very commonly in folliculitis decalvans (FD).
The patient was started on topical steroids and steroid injections together with hydroxychloroquine. The patient will be seen back in 3 months to review response to treatment. Blood tests will be needed monthly for three straight months for CBC, AST, ALT while starting hydroxychloroquine. An eye examination will be needed within 6 months. Clinical photos and trichoscopic photos were taken at the first visit and wil be compared to photos taken a the 3 months follow up. The hope is that redness will be reduced and that that patient’s perception of increased shedding will be reduced. I will monitor over time if more hair loss occurs. Regrowth may or may not occur in scarring Alopecias and this is not a main goal. The goal of treatment is to stop it from getting worse.
Article orginally posted at donovanmedical.com