Discussion
The most prevalent symptoms of penile abscess, a rare urological illness, are painful erections and localized penile swelling. Although the causes of penile abscess vary, they are often linked to injections, disseminated infections and penile trauma. Furthermore, numerous occurrences of spontaneous penile abscess are described without an underlying cause or inciting event. Primary, secondary and idiopathic penile abscesses are distinguished based on their etiology. While secondary abscesses are associated with perianal, perineal, or intra-abdominal abscesses and/or hematogenous diffusion, primary abscesses were associated with intracavernosal injection, penile trauma and iatrogenic causes (2). Physical examinations occasionally reveal inguinal lymphadenopathy or scrotal abscesses. As the etiology of penile abscess could be linked to perianal abscess, digital rectal examination are recommended to be performed methodically (28). Additionally, the presentation of tuberculosis-related penile abscess is typically more progressive and ‘silent’ (the presentation of tuberculosis-related penile abscess is not easily noticeable or symptomatic until the condition becomes more severe or advanced. It typically progresses without clear or prominent symptoms until it reaches a more critical stage) (29,30).
The variety of organisms cultivated from abscess swabs reflect the diverse etiologies of penile abscess. The following organisms have been isolated in various case reports: Staphylococcus aureus, Escherichia coli, Mycobacterium tuberculosis, Prevotella bivia, Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius. The most frequently implicated species in penile abscess, as reported by Dugdale et al (2) are Staphylococcus aureus, Streptococcus, Bacteroides and Fusobacteria (2). Apart from infection, penile abscesses are also associated with diabetes mellitus (16,20) and other forms of immunosuppression due to steroid abuse (25). As demonstrated in a previous study, it remains unclear whether the corpora cavernosa is resistant to the hematogenous spread of infection (22). However, there have been a few accounts, including one regarding a case in which the hematogenous dispersion of dental caries was reported to result in penile abscess (9,31). Of note, two distinct microbiological scenarios have been identified. When abscesses have a localized origin, the causative organisms are usually skin-related (Staphylococcus aureus, Staphylococcus epidermidis). Under certain conditions, these microbes act as opportunistic pathogens, despite being part of the normal microflora (2,5). By contrast, when no clear portal of bacterial entry is identified, the primary pathogens originate from dental commensal flora (9).
In the past, aspiration and clinical examination served as the primary diagnostic methods for penile abscess. However, with the advancement of medical technology, various imaging modalities, such as CT scans, US and MRI, are utilized to confirm the diagnosis (32). The majority of studies included in the present systematic review reported that MRI and US were used to evaluate penile abscess cases. Among these, US served as the main imaging technique (33), given its noninvasive nature and the ability to perform bedside procedures including simultaneous abscess drainage. When moderate cases were assessed with extracranial doppler with color US, findings included significant hyperemia of the cavernous bodies, thickened mucosa, increased echogenicity of subcutaneous tissues and heterogeneous hypoechoic areas. In severe cases, B-mode US has revealed anechoic or hypoechoic collections with sediment and poorly defined margins (34). CT scans, although less frequently used due to radiation and low soft tissue contrast, assist in drainage guidance, abscess localization and the evaluation of adjacent structure involvement. When contrast agents are administered, CT scans reveal fluid accumulation, occasional air bubbles, perilesional fat edema and wall hyperemia. MRI, when available, provides superior soft tissue contrast and allows for surgical planning, tissue plane characterization, and the exclusion of other pelvic or perineal infection foci. On an MRI, penile abscesses exhibit a low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, with rim enhancement following gadolinium administration (35). CT or MRI assess disease extension to the perineum, abdominal wall, fascial planes and buttocks. Nonetheless, it is suggested that the selection of imaging modality should be tailored to individual cases due to the lack of consensus on the most appropriate approach for this rare presentation.
Management options for penile abscess consist of intravenous antibiotic therapy combined with either open surgical incision and drainage (11) or radiologically guided needle aspiration (32). Antibiotic therapy is ideally based on culture and sensitivity results, although empirical therapy is frequently initiated. Despite the appeal of conservative treatment, the surgical approach, although invasive and associated with complications, remains the primary choice due to the risk of recurrence with incomplete evacuation (2). Surgical drainage is performed in cases that develop spontaneously or are exacerbated by trauma, disseminated infection, or failed conservative therapy. This approach enables the simultaneous treatment of the abscess and its underlying cause. Additionally, it allows surgeons to assess anatomical damage (1).
Several studies reported the use of broad-spectrum antibiotics as first-line therapy, particularly ceftriaxone, vancomycin and piperacillin-tazobactam (2). These were often administered intravenously and were selected based on either empirical judgment or microbial culture results. Treatment duration ranged from 7 to 14 days in the majority of cases. However, due to the nature of case reports, detailed dosing information was inconsistently provided, limiting standardized interpretation of efficacy across cases. However, some cases were successfully managed using less invasive interventional techniques, such as image-guided aspiration and antibiotics (16,20). Image-guided needle aspiration, performed under local anesthesia, minimizes tissue trauma and reduced the risk of postoperative complications like fibrosis (32). Among these, US-guided coaxial puncture and rinsing has emerged as a promising method (3), owing to its simplicity, cost-effectiveness and minimal equipment requirements. The real-time monitoring capability of US enables the accurate visualization of the abscess cavity throughout treatment. The coaxial aspiration/flushing technique has proven to be particularly effective for superficial subcutaneous abscesses. However, in cases involving deep abscesses seen in preoperative imaging, this method is deemed insufficient for complete evacuation and washout. Thus, open incision and drainage remain the gold standard for thorough debridement and concurrent pathology assessment (3,16,33). Close post-operative monitoring is emphasized regardless of the treatment method. For instance, Ehara et al (11) reported a case of a 54-year-old patient who underwent open surgical drainage for a cavernosal abscess; however, 3 weeks later, the patient developed a recurrent abscess caused by methicillin-resistant Staphylococcus aureus, requiring total penectomy
In addition to therapeutic strategies, several underlying risk factors have been observed to increase patient susceptibility to penile abscess. These include diabetes mellitus, long-term immunosuppressive therapy, poor hygiene, sexually transmitted infections and intracavernosal injections. Conditions, such as uncontrolled diabetes and systemic immunosuppression may compromise host defense mechanisms, allowing bacterial invasion and abscess formation. The awareness and management of these risk factors are essential for both prevention and early intervention (1-4,6,12,15).
Post-operative complications, such as penile curvature, fibrosis and erectile dysfunction have been reported, although the majority of patients have been shown to regain normal anatomy and erectile function. The present systematic review identified secondary fibrosis and resultant penile deviation, as well as erectile dysfunction as the most common sequelae. Compared to US-guided aspiration, these complications occurred more frequently following open surgical drainage. Consequently, some patients required penile prosthesis or further surgical intervention to manage these issues (22). In one case of cavernositis, the patient presented within 36 h of symptom onset and did not experience erectile dysfunction after drainage. This case, as reported by Shamloul et al (24), suggested that early intervention may preserve erectile function by limiting cavernosal necrosis and fibrosis.
Erectile dysfunction remains a potential complication, particularly in cases of delayed treatment or surgical trauma (20). Although its precise pathogenesis remains unclear, it is considered to involve multiple mechanisms including fibrosis, penile curvature and impaired vascular supply. In the majority of cases, fibrosis and curvature do not require correction, although they could significantly affect erectile quality (1). Additional contributors to erectile dysfunction include impaired blood flow, nerve injury, hormonal disturbances and tissue pathology (36). Venous occlusion and endothelial dysfunction also play a role (37). Given the complex integration of neurologic, vascular and hormonal systems required for erectile function, further investigations are warranted to clarify the exact mechanisms linking penile abscess to erectile dysfunction (38). Thus, further research and clinical assessment are necessary to fully understand the specific mechanisms of erectile dysfunction following a penile abscess.
The present systematic review represents, to the best of our knowledge, the first comprehensive synthesis of complications and outcomes associated with penile abscess. Nonetheless, it was limited by the nature of the included literature, which consisted entirely of case reports and case series. Additionally, the restriction to English-language studies reduced the pool of eligible publications. Conducting multicenter research in this field remains challenging due to the clinical complexity and rarity of such cases. The limited sample size also constituted a major limitation of the present systematic review.
In conclusion, in the present systematic review, case reports on the clinical outcomes and complications of penile abscesses were synthesized and analyzed. Although several complications were reported, as reported in the included studies generally demonstrated favorable clinical outcomes, despite the inherent risk of postoperative complications. Early diagnosis and prompt treatment remained the key to successful management.
Given the predominance of systemic antibiotics and surgical drainage in current management, these modalities continue to serve as a reliable therapeutic backbone. Broad-spectrum antibiotics, such as ceftriaxone, vancomycin and piperacillin-tazobactam are commonly used, either empirically or guided by culture results. In the majority of the reported cases, antibiotics were administered intravenously with a duration ranging from 7 to 14 days, depending on the clinical response. However, detailed information on dosage was inconsistently reported across case studies, limiting definitive conclusions on optimal therapeutic regimens. these modalities continue to serve as a reliable therapeutic backbone. However, less invasive techniques, such as image-guided aspiration, have exhibited encouraging results in reducing postoperative complications and preserving erectile function. Therefore, incorporating these approaches into clinical decision-making may enhance patient outcomes and reduce the need for extensive interventions. Patients should be closely monitored post-operatively for adverse effects, particularly erectile dysfunction and penile deviation, which were the most commonly reported complications. These findings should be applied with caution in clinical practice. As regards adverse effects, erectile dysfunction and penile deviation were the most commonly reported complications.
Additionally, the awareness of patient-specific risk factors, such as diabetes mellitus, immunosuppressive conditions and a history of intracavernosal injection, may help clinicians identify vulnerable individuals and implement early preventative or therapeutic measures.