# Hard Flaccid Syndrome

Hard flaccid syndrome (HFS), also known as hard flaccid (HF), is a rare, chronic condition characterized by a flaccid penis that remains in a firm, semi-rigid state in the absence of sexual arousal. Patients describe their flaccid penises as being firm to the touch, rubbery, shrunken, and retracted. This may be accompanied by pain, discomfort, and a range of additional symptoms. Though the exact cause is poorly understood, current research suggests that HFS is the result of excessive sympathetic activity in the smooth muscle tissue of the penis that is induced by a pathological activation of a theorized pelvic/pudendal-hypogastric reflex. This reflex is thought to be triggered by an injury to the erect penis, blunt trauma to the perineum, and cauda equina, among others. An emerging theory suggests that the real explanation for HFS is sympathetic nerve sprouting in the dorsal root ganglia following a peripheral nerve injury. The majority of patients are in their 20s–30s and symptoms significantly affect one's quality of life. Treatment usually involves a multi-modal approach utilizing a combination of alpha blockers, PDE5 inhibitors, and specialized pelvic floor physical therapy though there isn't much evidence to support their efficacy and most patients reportedly do not benefit from currently available treatment options. Due to limited awareness and understanding of the condition within the scientific and medical communities, definitive treatment for HFS does not exist.

## Signs and Symptoms

The most obvious, unmistakable, and defining symptom of Hard Flaccid Syndrome is a penis that remains in a firm, semi-rigid state in the absence sexual arousal. The flaccid penis will appear shrunken, contracted, and upon palpation will feel hard and non-compressible. This typically worsens when the patient is in a standing position. The skin on the shaft of the flaccid penis may also have folds or wrinkles, resembling gastric and vaginal rugae.

#### Other Signs and Symptoms

In addition to a "hard flaccid" penis, patients may also experience erectile dysfunction (difficulty achieving or maintaining an erection; painful or tight erections; penis doesn't fill up completely when getting an erection; no morning erections; no nocturnal erections; no spontaneous erections; painful nocturnal erections), sensory changes (a persistent feeling of coldness in the glans, shaft, or entire penis; paresthesia or pins and needles in or around the penis; dysesthesia or an unpleasant, abnormal sense of touch in or around the penis; complete or partial loss of erogenous sensation to the penis; complete or partial loss of tactile feeling to the penis including temperature, pressure, vibration, or texture; penis feels “hollow,” “disconnected” or unstable, as if it was not a part of the body), physical or structural changes to the penis (an hourglass or bottleneck shape to the penis during the flaccid or semi-erect states; engorged veins or spider veins; discoloration of the skin of the penis; soft glans; “long flaccid,” where the flaccid penis is more extended than it should be and either feels firm or like a balloon filled with water; tilt of the penis to one side while flaccid, erect, or both; rotation of the penis when erect), pain (pain in or around the penis; pain in or around the penis or perineum after ejaculation), testicular retraction, urinary issues (incontinence; urgency; duel urine streams; a burning feeling when urinating), pelvic floor dysfunction, and constipation.

## Cause

Although the exact cause and mechanism are not fully understood, the general consensus is that Hard Flaccid Syndrome is caused by excessive sympathetic activity, or tone, in the erectile smooth muscle tissue. This heightened activity leads to relentless smooth muscle contraction, which produces the "hard flaccid" state, or the persistent firmness and semi-rigidity of the flaccid penis that is characteristic of the condition. This is supported by the fact that intracavernous injections of phentolamine, an α-adrenergic antagonist, eliminate the "hard flaccid" state, albeit temporarily.

#### Pathology

The leading theory suggests that HFS is the result of a pathological activation of a theorized pelvic/pudendal-hypogastric reflex with the afferent limb being the dorsal branch of the pudendal nerve.
Needs expansion. Expansion in progress...

## Diagnosis

At the moment, there is no established schema or procedure for diagnosing Hard Flaccid Syndrome in a clinical setting. Due to the condition's relative obscurity within the medical community, the majority of HFS patients diagnose themselves.

## Treatment

Definitive treatment for Hard Flaccid Syndrome does not exist and current methods often fail to relieve symptoms for most patients. The complexity and poorly understood nature of HFS makes it very difficult to treat. As a result, there is a growing need for more research that can provide better outcomes for those suffering from this challenging condition.

#### Current Treatment Options

* Alpha blockers (Doxazosin, Tamsulosin)
* PDE5 inhibitors
* Low-intensity shock wave therapy
* Analgesics
* Anti-inflammatory agents
* Pelvic floor physical therapy
* Neural inhibitory agents (Pregabalin, Gabapentin, Amitriptyline)
* Skeletal muscle relaxing agents (Piazepam)
* Spine surgery (only for patients presenting with cauda equina)

#### Potential Treatment Options

At present, the following treatment options have not been explored in scientific or medical literature in relation to HFS directly, though they could yield positive outcomes in the future.
* Percutaneous lumbar sympathectomy
* Repeated sympathetic nerve blocks
* Dorsal root ganglion stimulation
* Botox
* ROCK inhibitors