Dermatology Online Journal

Eruptive vellus hair cysts
Utpal Patel MD PhD, Vitaly Terushkin MD, Max Fischer MD, Hideko Kamino MD, Rishi Patel MD
Dermatology Online Journal 18 (12): 7

The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York

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Abstract

Eruptive vellus hair cyst (EVHC), described initially in 1977, is a benign dermatologic condition that is characterized by the sudden appearance of monomorphic, follicular, asymptomatic, small papules in children and young adults. The diagnosis is based on the histopathologic findings of stratified-squamous epithelium with a granular layer that surrounds a cystic space filled with laminated keratin and a variable number of vellus hair cysts. EVHC can be associated with steatocystoma multiplex. A current hypothesis suggests that EVHC originates from a cystic change at the insertion of the pilosebaceous duct. EVHC is primarily treated for cosmesis with retinoids, surgery, and lasers.

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History

Figure 1	Figure 2

A 23-year-old woman presented to the Charles C. Harris Skin and Cancer Pavilion with asymptomatic papules on the abdomen for approximately three months. A diagnosis of folliculitis initially was made and she was treated with tretinoin 0.05 percent cream and benzoyl peroxide gel. One month later, the patient reported treatment failure and noted a thick white discharge from a few of the papules. Review of systems was not contributory. No family members had similar lesions. A biopsy was performed to confirm the diagnosis.

Past medical history included psoriatic arthritis that was managed with infliximab 50 mg every week and topical clobetasol ointment for over six years. Family history included systemic lupus erythematosus in the mother.

Physical examination

Multiple, 1 to 2 mm follicular, skin colored papules were scattered on the abdomen.

Laboratory data

None.

Histopathology

Within the dermis, there is a cystic space lined by a thin squamous epithelium and containing loose orthokeratin and many vellus hair shafts.

Discussion

Eruptive vellus hair cysts (EVHC), initially were described in 1977 in two children, are a persistent eruption of monomorphous, skin-colored papules that have the diagnostic histopathologic findings of vellus hair shafts within a cystic space [1]. To date, there are about 220 described cases of EVHC [2]. The average age of diagnosis is 24 years (range 1 to 84) whereas the onset is approximately 17 years, with 90 percent being under the age of 35. Overall, there is no racial or gender preference (F:M ratio of 1.3). Over 90 percent of patients are asymptomatic, with pruritus being the most common symptom. The lesions tend to be small (1 to 7 mm), skin-colored, dome-shaped papules with a smooth texture. Spontaneous or pressure-induced discharge of whitish material has been described. Lesions can range from solitary to hundreds. The distribution tends to be symmetric and generalized, with the central abdomen being the most common site of involvement (65%). The diagnosis rests on the histopathologic findings of mid-dermal cysts that are lined by stratified-squamous epithelium, with a granular layer that surrounds a cystic space filled with laminated keratin and a variable number of vellus hair cysts. The diagnosis also can be made by performing a 10 percent potassium hydroxide preparation of cyst contents, which shows vellus hairs [3]. Without treatment, EVHC can be persistent or undergo slow spontaneous regression.

Nineteen familial cases of EVHC have been described [2]. Familial EVHC is characterized by autosomal dominant transmission with complete penetrance, early age of onset (nine years), and a tendency toward persistence. Late onset EVHC (35 years or older) primarily is described in Asian women and is characterized by the appearance of a solitary lesion on the face or anterior chest, with an average age of onset of 57 years.

In the literature a wide variety of associated conditions have been described. However, steatocystoma multiplex is likely to be the only condition that is associated with EVHC (described in 5% of cases of EVHC) [4]. On histopathologic examination, 4 percent of cases have been described to show sebaceous lobules or cells within the cystic wall. Based on this finding, the origin of EVHC has been hypothesized to be follicular, specifically near the confluence of the sebaceous duct and the hair follicle [4].

Treatment of EVHC is primarily cosmetic in nature. The most successful therapies have been the use of topical tretinoin cream (14 of 15 cases) and destructive methods, which include surgery (7 of 7 cases), carbon dioxide (4 of 4 cases), and Erbium:YAG laser (5 of 6 cases) [2, 5-8]. However, the data are based on case reports and small case series and thus have bias that leads to false high success rates. In the case presented, the patient is being treated with topical tretinoin 0.05 percent cream.

References

1. Esterly NB, et al. Eruptive vellus hair cysts. Arch Dermatol 1977; 113:500 [PubMed]

2. Torchia D, et al. Eruptive vellus hair cysts: a systematic review. Am J Clin Dermatol 2012 Feb 1;13(1):19-28. [PubMed]

3. Hong SD, Frieden IJ. Diagnosing eruptive vellus hair cysts. Pediatr Dermatol 2001; 18:258 [PubMed]

4. Ohtake N, et al. Relationship between steatocystoma multiplex and eruptive vellus hair cysts. J Am Acad Dermatol 1992; 26:876 [PubMed]

5. Fisher DA. Retinoic acid in the treatment of eruptive vellus hair cysts. J Am Acad Dermatol 1981; 5:221 [PubMed]

6. Senayli A, et al. Surgical treatment approach in a patient with eruptive vellus hair cyst. Gulhane Med J 2007; 49:46

7. Huerter CJ, Wheeland RG. Multiple eruptive vellus hair cysts treated with carbon dioxide laser vaporization. J Dermatol Surg Oncol 1987; 13:260 [PubMed]

8. Helbig D, et al. Comparative treatment of multiple vellus hair cysts with the 2940 nm Er:YAG and 1540 nm Er:Glass laser. J Cosmet Laser Ther 2011; 13:223 [PubMed]

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