Diagnosis and Management of Pearly Penile Papules

Abstract

Pearly penile papules (PPP) are common, benign lesions that appear on the corona of the glans penis during adolescence or early adulthood. Despite their benign nature, PPP are known to cause significant distress because of their resemblance to sexually transmitted infections such as condyloma acuminata. PPP can be clinically distinguished based on their uniform, dome-shaped papules that orient in one to two rows around the glans penis. There is no association between PPP and sexually transmitted infections, and treatment is generally reserved for patients with excessive concern. Physicians should be aware of this distinction in order to adequately reassure anxious patients. For patients who still desire treatment after counseling, cryotherapy and laser therapy represent two reliable treatment options with low rates of recurrence.

Introduction

Pearly penile papules (PPP) are painless and benign lesions that present in rows around the corona of the glans penis in late adolescence or early adulthood. Although asymptomatic, they are often mistaken for sexually transmitted infections such as condyloma acuminata (Oates, 1997).

Originally described by Littré and Morgagni in 1700, PPP have been given various names throughout history, including hirsutoid papilloma, papillomatosis corona penis, and corona capillitii (Agrawal, Bhattacharya, & Singh, 2004). Johnson and Baxter (1964) were the first to coin the term PPP in 1964. Although the function of PPP is poorly understood, it is thought that they are vestigial, as similar structures are seen in other mammals (Callomon & Wilson, 1956).

Presentation

PPP are present in 14% to 48% of males, although the prevalence varies among specific populations (Agrawal et al., 2004; Michajlowski, Sobjanek, Michajlowski, Wlodarkiewicz, & Matuszewski, 2012; Sonnex & Dockerty, 1999). The lesions usually present as pink or white, dome-shaped or filiform papules that are one to two millimeters in diameter and one to four millimeters in height, orienting around the corona of the glans penis usually in one to two rows (Figure 1; Agrawal et al., 2004; Michajlowski et al., 2012; Oates, 1997). PPP are most prominent along the dorsal side of the corona and may encircle the glans entirely, although lesions have also been reported ectopically on the shaft of the penis (Neri, Bardazzi, Raone, Negosanti, & Patrizi, 1997; O’Neil & Hansen, 1995). Lesions are rarely seen in prepubertal children and most often present during the late stages of puberty (Glicksman & Freeman, 1966; Neri et al., 1997; Oates, 1997). The prevalence declines in older patients, suggesting that the lesions regress with age (Agha et al., 2009; Glicksman & Freeman, 1966). Circumcised males have lower rates of PPP, possibly due to chronic abrasion to the exposed corona causing lesion regression (Agha et al., 2009; Michajlowski et al., 2012; Neinstein & Goldenring, 1984; Vesper, Messina, Glass, & Fenske, 1995). There is some evidence that PPP are more common in the Black population (Rehbein, 1977), but many studies have reported no association with race (Glicksman & Freeman, 1966; Neinstein & Goldenring, 1984).

Figure 1.

(a) Clinical photograph demonstrating dome-shaped papules along the corona of the glans penis. (b) Dermoscopic image illustrating PPP with comma-shaped vessels.

Unfamiliarity of the benign nature of PPP often leads to significant anxiety and fear of having a sexually transmitted infection. A retrospective study in Singapore reported that more than 14% of men who initially presented to a sexually transmitted infection clinic had exclusively PPP without any evidence of infection (Khoo & Cheong, 1995). This misconception can also lead to strained relationships, as fear of a possible sexually transmitted infection calls into question the fidelity between partners (Monroe, 2009). The degree of concern has even been correlated to the size of the papules. In one questionnaire study, significant worry was reported in 63% of patients with moderate or large papules, compared with 33% of patients with barely perceptible PPP (Sonnex & Dockerty, 1999).

The differential diagnosis includes condyloma acuminata, Tyson’s glands, or molluscum contagiosum. PPP do not contain human papillomavirus (Ferenczy, Richart, & Wright, 1991), and there is no association between condyloma and the presence of PPP (Hogewoning et al., 2003). Unlike Tyson’s glands, which are modified sebaceous glands in a parafrenular distribution, PPP are not predominantly parafrenular and have no glandular component (Ackerman & Kronberg, 1973). Molluscum contagiosum can be distinguished clinically from PPP based on their umbilicated papules that are larger in size (Agrawal et al., 2004; O’Neil & Hansen, 1995). Despite the fact that PPP can be easily distinguished from more serious diagnoses, one study indicated that 38% of affected men reported being concerned or worried about their lesions, and nearly half of those who learned of their benign nature still wanted them removed (Sonnex & Dockerty, 1999).

On dermoscopy, PPP appear white or pink in a cobblestone or grape-like pattern with each papule containing central dotted or comma-shaped vessels (Figure 1; Ozeki, Saito, & Tanaka, 2008; Watanabe, Yoshida, & Yamamoto, 2010). This vessel architecture is nonspecific and can also be seen in condyloma (Watanabe et al., 2010). Unlike warts, however, PPP do not have desquamation, which is seen as an irregular reflection on dermoscopy (Ozeki et al., 2008).

The histology of PPP is similar to that of acral angiofibromas, and for this reason they have been proposed as a subcategory (Oates, 1997; Ozeki et al., 2008). The histological findings include increased epidermal melanocytes overlying a prominent granular zone with absent basal layer pigment (Glicksman & Freeman, 1966; Neinstein & Goldenring, 1984). Increased vasculature is seen in the upper dermis with focally elongated rete ridges (Oates, 1997; Ozeki et al., 2008; Vesper et al., 1995; Watanabe et al., 2010). The dermis also contains infiltration of lymphocytes and histiocytes (Oates, 1997; Ozeki et al., 2008). Last, a whorled collagen pattern is seen with increased spindle-shaped stellate fibroblasts (Ackerman & Kronberg, 1973; Agrawal et al., 2004).

Treatment

Because of the benign nature of PPP as well as their regression with age, treatment is generally reserved for patients who suffer extensive embarrassment or concern. Cryotherapy and lasers have been reported in such cases. One study performed two sessions of cryotherapy in four patients and cleared 80% to 90% of lesions without complications (Ocampo-Candiani & Cueva-Rodriguez, 1996). Another case report of a patient with dark skin described similarly successful results with no pigmentation changes and no lesion recurrence after 2 years (Porter & Bunker, 2000).

Various groups have reported successful and complete clearance of PPP with CO₂ laser ablation. The high vascularity of penile tissue allows for rapid healing after laser-induced thermal injury, but this also predisposes the patient to bleeding during the procedure. The continuous wave mode of the CO₂ laser provides better hemostasis and operative field visualization than the short pulse mode (McKinlay, Graham, & Ross, 1999). Using the fractionated CO₂ laser, one group reported more than 90% resolution after a single treatment (Krakowski, Feldstein, & Shumaker, 2015). Another group concluded that two to three treatments were sufficient to completely resolve lesions without adverse effects in both light and dark skin types (Gan & Graber, 2015). While the CO₂ laser exposes the underlying tissue, reepithelialization generally occurs within 5 to 7 days (Krakowski et al., 2015). Nevertheless, the procedure requires anesthesia and increases the risk of scarring and infection. Additionally, the postoperative management, including home dressing changes, can be inconvenient to patients (Rokhsar & Ilyas, 2008). The CO₂ laser can also lead to postinflammatory pigmentation changes in dark skin types. Despite this fact, two groups reported complete lesion resolution with no adverse pigmentary events (Lane, Peterson, & Ratz, 2002; Magid & Garden, 1989).

Using the ablative 2940-nm Er:YAG laser, Baumgartner treated 45 patients for one to six sessions. All lesions were successfully cleared with no adverse effects and no recurrence after 1 year. Notably, many of the patients in this study had prior failed treatment attempts with agents such as podophyllin, cryotherapy, and topical fluorouracil plus salicylic acid. Ablated areas healed within 2 weeks after treatment. Despite sustaining up to six laser sessions, no scarring or pigmentation changes were noted (Baumgartner, 2012).

Fractional resurfacing with the 1550-nm erbium laser has shown complete clearance in one patient after five treatment sessions. Unlike ablative approaches, this laser was relatively painless and did not produce open wounds in the skin. Additionally, there was no lesion recurrence after 1 year (Rokhsar & Ilyas, 2008).

The pulsed dye laser has also shown significant lesion clearance with minimal discomfort. In a study involving four patients, Sapra, Sapra, and Singh (2013) achieved complete resolution in three patients after two to three treatments. The remaining patient was satisfied with the results after one treatment. Future laser therapies will likely focus on nonablative approaches, such as the pulsed dye laser, to adequately and painlessly treat PPP without the risk of infection or scarring. Although typically reserved for special scenarios, laser treatment of PPP produces favorable cosmetic results with a low risk of adverse effects and recurrence.

Conclusion

PPP are common, asymptomatic lesions that can cause serious concern for patients despite their benign nature. The fear of sexually transmitted infections can cause significant distress in male and female patients alike, severely affecting quality of life. Understandably, a new or recently discovered genital lesion can send patients running to their doctors. While frequent misdiagnosis of benign lesions such as PPP perpetuates patient anxiety, these lesions can be both clinically and histologically distinguished from more serious conditions such as condyloma acuminata. Reassurance is the most appropriate course of action, although treatment options such as laser and cryotherapy are available for patients with significant distress. It is important for physicians to be aware of this common mimicker in order to provide appropriate management.