Sleep state misperception (SSM) is a term in the International Classification of Sleep Disorders (ICSD) most commonly used for people who mistakenly perceive their sleep as wakefulness, though it has been proposed that it be applied to those who severely overestimate their sleep time as well ("positive" sleep state misperception). While most sleepers with this condition will report not having slept in the previous night at all or having slept very little, clinical recordings generally show normal sleep patterns. Though the sleep patterns found in those with SSM have long been considered indistinguishable from those without, some preliminary research suggest there may be subtle differences (see Symptoms and diagnosis: Spectral analysis).Patients are otherwise generally in good  health, and any illnesses—such as depression—appear to be more associated with fear of negative consequences of insomnia ("insomnia phobia") than from any actual loss of sleep.Sleep state misperception was adopted by the ICSD to replace two previous diagnostic terminologies: "subjective insomnia complaint without objective findings" and "subjective sleepiness complaint without objective findings. "The validity and reliability of sleep state misperception as a pertinent diagnosis has been questioned, with studies finding poor empirical support. Classification
Sleep state misperception is classified as an intrinsic dyssomnia. While SSM is regarded a sub-type of insomnia, it is also established as a separate sleep-condition, with distinct pathophysiology.
Prurigo simplex is a chronic, itchy, idiopathic skin condition characterized by extremely itchy skin nodules and lesions. : 57  Typically, there is no known direct cause of prurigo simplex, but some factors are known to trigger or aggravate it. This condition falls between chronic and acute, sometimes transitioning into a chronic condition. Many people experience a recurrence of the condition after periods of remission. Middle-aged patients are the most prone age group to this condition. Presentation
The most common prurigo simplex symptoms are skin nodules resembling insect bites that are intensely itchy. These nodules are frequently scratched open, becoming lesions that continue to itch. Sometimes the skin thickens and becomes discolored around the nodules. The scalp, arms, legs and trunk of the body are the most frequent sites of the bumps and lesions. Itching can become severe and habitual, worsening the condition and possibly causing infections in the open sores. Treatment
Treatment is challenging, with narrow band UVB or pimozide sometimes helpful. Prognosis
Sometimes the nodules become less itchy and eventually disappear leaving a discolored area or scar tissue. The same nodules can persist for months or even years, though, without healing. Patients may experience a remission but then relapse with new nodules forming. The condition might also become chronic, with no periods of improvement and relief. == References ==