Rare Sexual Disorders in Men May Challenge Diagnosis

Erectile dysfunction, premature ejaculation, and hypogonadism are common clinical diagnoses. Beyond established guidelines, however, there is a group of rare sexual disorders in men that are often overlooked or prematurely classified as psychogenic disorders. For affected individuals, this can lead to prolonged evaluation across multiple specialties and substantial impairment of their quality of life, intimate relationships, and mental health.

A review published in Nature Reviews Urology summarizes the current evidence on seven of these conditions.

• Post-finasteride syndrome (PFS)

• Restless genital syndrome (ReGS)

• Postorgasmic illness syndrome (POIS)

• Post-selective serotonin reuptake inhibitor (SSRI) sexual dysfunction (PSSD)

• Hard flaccid syndrome (HFS)

• Sleep-related painful erections (SRPE)

• Post-retinoid sexual dysfunction (PRSD)

The evidence is derived mainly from case series, observational studies, and pharmacovigilance data, with the absence of randomized trials. Therefore, the etiology, diagnosis, and management of these conditions remain incompletely defined.

1. Drug-Induced Syndromes

Several of these conditions share a defining feature: Sexual symptoms persist even after discontinuation of the causative agent. These findings have direct implications for diagnosis and management.

PFS

PFS refers to persistent sexual, physical, and psychological symptoms after the discontinuation of 5-alpha reductase inhibitors, such as finasteride or dutasteride. Clinical features include reduced libido, erectile dysfunction, decreased genital sensitivity, and orgasmic dysfunction. Depressive symptoms, anxiety, and cognitive impairment may also occur.

Proposed mechanisms include alterations in neuroactive steroids in the cerebrospinal fluid and plasma, changes in androgen receptor expression, structural changes in the corpus cavernosum observed in animal models, and genetic polymorphisms of androgen receptors. Alterations in the gut microbiota have also been reported. Pharmacovigilance data are prone to reporting and selection bias, and media coverage may influence how and when individuals seek care.

This condition is diagnosed by exclusion. Persistent sexual dysfunction lasting for at least 3 months after discontinuation is a core criterion. Preexisting sexual or psychiatric conditions should be considered in the differential diagnosis. No evidence-based treatment exists, although individual case reports have described hormonal or symptom-directed approaches. Diagnosis should not be made in individuals with prior exposure to isotretinoin or SSRI.

PSSD

Adverse sexual effects associated with SSRI therapy are well recognized. PSSD describes persistent dysfunction after drug discontinuation. The reported symptoms include genital anesthesia, reduced libido, anorgasmia, erectile dysfunction, and altered ejaculation. Symptoms are not necessarily dose-dependent and may occur after brief exposures.

In 2019, the European Medicines Agency recommended updating product information for SSRI and serotonin-norepinephrine reuptake inhibitors to include warnings about persistent sexual dysfunction after discontinuation.

Proposed mechanisms include sustained serotonergic dysregulation, alterations in 5-HT receptors, and epigenetic changes. Serotonin inhibits sexual function, whereas dopamine plays a stimulatory role. Animal studies suggest that early SSRI exposure may have long-term effects on sexual behavior.

Diagnosis requires a thorough medical history, with careful assessment of the temporal relationship to medication use and exclusion of depression-related sexual dysfunction. Treatment options remain limited and are based on individual cases, such as switching to dopaminergic antidepressants or vortioxetine. Although spontaneous improvement has been reported, recovery may take several years.

PRSD

Isotretinoin is widely used to treat severe acne vulgaris. Adverse sexual effects, particularly erectile dysfunction and loss of libido, have been reported as possible side effects, with symptoms persisting even after treatment discontinuation. In some individuals, symptoms appear or worsen after discontinuation of the medication.

Animal studies demonstrated the effects of retinoids on the male reproductive system, including changes in testosterone levels and spermatogenesis. Hormonal alterations in humans may normalize after discontinuation. A serotonergic mechanism has been proposed but remains unproven.

Diagnosis relies on clinical history and exclusion of other causes. No specific treatment exists, and management is symptom-directed.

2. Neuropathic and Functional Syndromes

ReGS

ReGS is characterized by persistent, unpleasurable genital dysesthesia, often described as a sensation of impending orgasm without sexual desire. Symptoms may worsen with sitting and are associated with significant psychological distress.

Evidence suggests the involvement of small fiber neuropathy affecting the dorsal penile or pudendal nerves. Several dopaminergic mechanisms have been proposed. This condition is not primarily associated with preexisting psychiatric disorders.

Treatment approaches include paroxetine, diazepam, pregabalin, transcutaneous electrical nerve stimulation, and pramipexole, with varying outcomes. Differential diagnoses include urologic, neurologic, and psychosomatic conditions.

HFS

HFS is characterized by a penis that remains in a firm, semi-rigid, or shriveled state, accompanied by sensory changes, cold sensation, pain, erectile dysfunction, and urinary symptoms. Preceding trauma, often during sexual activity or masturbation, is commonly reported in the literature.

Proposed mechanisms include pudendal neuropathy, local hypoxia, inflammation, and pelvic floor muscle spasms. Psychological factors, such as anxiety and depression, may contribute to symptom persistence and to chronic pain.

Imaging studies, such as Doppler ultrasonography or MRI, are often normal, which may lead to misdiagnosis as a psychogenic disorder. Management includes pelvic floor physiotherapy, psychological support, and symptom-directed pharmacotherapy, although the evidence remains limited.

3. Ejaculatory Syndromes

POIS

POIS is characterized by flu-like or allergy-like symptoms that occur within seconds to hours after ejaculation and persist for 2-7 days. Common features include fatigue, myalgia, difficulty in concentrating, rhinorrhea, and feverishness.

An immune response to components of semen has been proposed, supported by positive skin testing using autologous semen in some cases. Other hypotheses include neuroendocrine dysregulation, cytokine changes, and an opioid-like withdrawal response after the orgasm.

Diagnosis is based on a specific pattern of symptoms, their rapid onset relative to ejaculation, and their lasting persistence. Treatment approaches, such as desensitization therapy, nonsteroidal anti-inflammatory drugs, and silodosin, have been reported in individual case reports. There is currently no standardized therapy for this condition.

SRPE

SRPE is a rare form of parasomnia characterized by painful erections during REM sleep that awaken the individual. Daytime erections remain normal and painless. Episodes often last approximately 15 minutes and may result in sleep disruption, fatigue, and increased irritability.

The probable causes include pelvic floor hypertonicity, autonomic dysregulation, and neurovascular factors. An ischemic mechanism similar to that of priapism is unlikely to occur. Polysomnography often results in reduced sleep efficiencies.

Baclofen is the most studied treatment, with variable and often temporary benefits. Other pharmacologic options have been described on a case basis. However, invasive approaches are not recommended for this condition.

Clinical Implications

These conditions share several features, including low prevalence, absence of validated biomarkers, limited high-quality evidence, and substantial psychological burden. Many affected individuals reported that their symptoms were not taken seriously or were prematurely attributed to “psychogenic” causes without adequate evaluation.

A structured sexual and medication history is essential, particularly for individuals exposed to 5-alpha reductase inhibitors, SSRI, or retinoids. Clinicians should document baseline sexual function and discuss potential adverse effects before initiating treatment.

Persistent symptoms after discontinuation require careful differential diagnosis rather than a hasty referral to psychosomatic care. Multidisciplinary collaboration across urology, endocrinology, neurology, and psychosomatic medicine is required to address this issue. Recognizing these syndromes as potential organic conditions reflects the current evidence and supports more appropriate clinical management.

Further prospective studies and coordinated registries are needed to better define the prevalence, risk factors, and treatment strategies of this condition. Clinicians who encounter these conditions in practice can contribute through systematic documentation and participation in research.

Note: This article originally appeared on Medscape.