Differentiating human papillomavirus (HPV) folliculitis from molluscum contagiosum (MC) folliculitis over the beard area can be clinically challenging. Both can present as asymptomatic follicle-based papules, and the verrucous morphology of HPV infection and punctum of MC may not be appreciable in all cases.
The first case is a 26-year-old male who presented with a history of multiple asymptomatic lesions on the beard for 4 months.. Cutaneous examination showed multiple follicle-based skin-colored to pearly-white papules ( Figure 1A ). Dermoscopic examination under nonpolarized mode showed perifollicular pearly white clods ( Figure 1B ). Histology of a papule showed lobular epidermal acanthosis with prominent intracytoplasmic Henderson-Patterson bodies, consistent with a diagnosis of MC folliculitis ( Figure 1C ).
The second case is A 33-year-old male who had multiple asymptomatic skin lesions over the beard for the last 6 months. He denied any history of recent cosmetic procedures. Cutaneous examination revealed multiple follicle-based skin-colored flat-topped (2 mm X 3 mm) papules ( Figure 2A ). Dermoscopy showed a perifollicular mosaic pattern comprising a variable-shaped white knob-like area with or without central dotted and hairpin vessels ( Figure 2B ). Histology of a papule showed basket weave hyperkeratosis, hypergranulosis, moderate acanthosis, and koilocytes in upper stratum spinosum and granulosum, consistent with the diagnosis of verruca plana/HPV folliculitis ( Figure 2C ).
Figure 2 .
(A) Multiple follicle-based skin-colored verrucous flat-topped papules. (B) Dermoscopy (Heine Delta20®, 10X magnification) shows a perifollicular mosaic pattern comprising of a variable-shaped white knob-like area with or without central dotted and hairpin vessels. (C) Histology shows basket weave hyperkeratosis, hypergranulosis, moderate acanthosis, and koilocytes in upper stratum spinosum and granulosum (H & E, X50). Inset showing koilocytes (H & E, X400).
In both the patients, all the investigations, including HIV 1 and 2 serology, to rule out immunosuppression were negative.
MC folliculitis is rare and usually occurs in patients with either acquired or iatrogenic immunosuppression. The presence of flesh-colored to erythematous papules with or without central umbilication is the common presentation.
HPV can spread from infected materials during cosmetic procedures, resulting in cosmetic warts. It can also spread along the line of the trauma due to pseudo-Koebnerization of preexisting warts [ 2 ] . The case in the discussion was unique. Each of the flat-topped papules over the beard area was follicle-based compared to the clustered or linear arrangement described for cosmetic warts or pseudo-Koebnerization, respectively.
Under dermoscope, MC characteristically demonstrates a variable-shaped white clod and crown vessels with or without a central punctum. Other features described are rosette, dotted and radial vessels [ 1 , 2 ] .
Verruca vulgaris demonstrates grouped papillae with dotted and hairpin vessels surrounded by a whitish halo. In contrast, the verruca plana can have dotted vessels on a yellowish background [ 1 ] . We observed a mosaic pattern comprising a white knob-like area with or without a central hairpin or dotted vessel in the HPV folliculitis.
The dermoscopic features described for other infectious folliculitis are the following: dotted vessels in Malassezia folliculitis; broken hairs, corkscrew hairs, black dots, zigzag hairs, and morse code hairs in dermatophytic folliculitis; central round pustule with peripheral sparse dotted vessels in staphylococcal folliculitis; and Demodex tails, and Demodex follicular openings in Demodex folliculitis. Another common mimicker, pseudo-olliculitis, demonstrates a U-shaped in-growing hair under a dermoscope [ 1 , 2 ] .
In conclusion, we report dermoscopic features of 2 rare cases of viral folliculitis on the beard. The dermoscopic examination can help differentiate between MC folliculitis from HPV folliculitis, with the former characterized by white clod and the latter by a mosaic pattern.
- Update on Dermoscopy and Infectious Skin Diseases Piccolo V. Dermatol Pract Concept.2019;10(1):e2020003. CrossRef PubMed
- High accuracy of recognition of common forms of folliculitis by dermoscopy: An observational study Durdu M, Errichetti E, Eskiocak AH, Ilkit M. J Am Acad Dermatol.2019;81(2):463-471. CrossRef PubMed
Figure 1 .
(A) Multiple follicle-based skin-colored to pearly-white (arrow) papules. (B) Dermoscopic examination (Heine Delta20®, 10X magnification) showing perifollicular pearly white clods. (C) Histology shows endophytic epithelial hyperplasia containing molluscum bodies (H & E, X50).