When treating patients with dysesthesia it is important to quantify their sensations and understand the sensations biologically, said Dr. Richard Fried, during a presentation at the American Academy of Dermatology (AAD) in Washington, D.C.
The umbrella term that is frequently used for uncomfortable or unpleasant sensations is dysesthesia, said Dr. Fried.
Patients with dysesthesia often feel numerous sensations such as pain, itch, burning, crawling, biting, and piercing, said Dr. Fried, a dermatologist who is also a clinical psychologist.
“It is important to biologize the symptoms of these patients. They need to know the sensations they are feeling are not just in their head,” suggested Dr. Fried, clinical director of Yardley Dermatology Associates and Yardley Clinical Research Associates in Yardley, Pa.
Dysesthesia, predisposing conditions
Clinicians must be cautious about the negative labelling of the condition because it may further stigmatize a patient, many of whom may have been told that they have a psychiatric issue. Dr. Fried recommends descriptive word usage such as cutaneous hypersensitive syndrome or neuropathic hypersensitive syndrome.
Dysesthesia can occur with or without obvious stimulation, Dr. Fried said. He added that “many of
the sensations happen as a result of an infection or because of traction or trauma.”
He explained that potential predisposing conditions that may lead to dysesthetic symptoms include diabetes, neuropathies, lyme disease, multiple sclerosis, tumours, metabolic abnormalities, spinal cord injury, alcohol withdrawal, surgery, or cosmetic filler injections.
There are also some psychiatric conditions associated with dysesthesia such as stress, depression, obsessive-compulsive disorder, body dysmorphic disorder, psychosis and delusions of parasitosis.
“We should promise every dysesthesia patient that we will stay absolutely vigilant to ensure there
is no active infection, infestation, inflammatory or autoimmune disease, organ dysfunction, metabolic
disturbance or malignancy,” he said.
Additionally, it is important to reassure these dysesthesia patients that they are not alone.
“Say to them ‘We have seen hundreds of patients with this skin disorder. We know that something has set off your skin nerve endings. I know that some people might be telling you this is a psychological problem, “in your head,” but it is not’,” said Dr. Fried. “These sensations are real and in your
skin. Of course, the intrusiveness and persistence can lead to anxiety, depression and despondency.”
Even if these patients do have psychiatric problems, do not be mislead into dismissing the dysesthesias as “psychogenic.” These are usually true depolarizations of cutaneous nerve endings, albeit sometimes amplified, he said.
Dr. Fried recommends that clinicians explain to their patients that when nerve endings become hyperactive or hypersensitive they begin to inappropriately overreact to environmental stimulation
such as perspiration, friction and the myriad of other cutaneous insults that occur daily.
“When nerve endings are in their usual state of function they are more tolerant of these daily insults,”
Dr. Fried said.
“So we should tell these patients that we are going to help their nerve endings respond more appropriately again. By doing this we are going to give these patients hope and control.”
Delusions of parasitosis Tx
For delusions of parasitosis, Dr. Fried explained that he believes there are two groups of patients,
and treatment for each group varies.
The first group are the classic delusional parasitosis patients, those who fully believe they are infested with bugs. They are very involved with the appearance and behaviour of the bugs, and frequently lack the extreme degree of panic and distress one might expect.
“These patients bring in a sample bag of cuts and clips. They are delighted to tell you [details] about
their bugs [such as] when they come out and what [the bugs] eat. The patient will also sometimes tell
you how [the bugs] mate,” said Dr. Fried.
The second group of patients are those who have been labelled as suffering from delusions of parasitosis. They are extremely concerned and distressed regarding their dysesthetic symptoms, but
usually present without samples and stories about the infesting agents. Dr. Fried suggests that those patients may have a cutaneous neuropathy, one which produces formications and other dysesthetic symptoms, leading to a belief of infestation.
Dr. Fried said that the ‘unsure’ delusional parasitosis patient who is fearful that they are infested may
benefit from very low dose pimozide, 0.5 or 1 mg HS.
“The classic delusional parasitosis patient, however, needs higher doses of pimozide—two to six milligrams—if they are going to respond to treatment.”
Interestingly, said Dr. Fried, researchers reported in a study published in the Journal of Drugs in
Dermatology (2012; 11(12):1506–1507) that antidepressant therapy (citalopram with dosing titrated
to 40 mg QD) was beneficial for patients previously labelled as having delusions of parasitosis. Perhaps the antidepressant allowed for decreased cutaneous symptoms, alleviation of anxiety and depression, and diminished psychologic preoccupation, he said.
This study probably revealed selective benefit for the dysesthetic patients with true psychosis.
However, Dr. Fried noted, clinicians now appreciate that ‘psychosis’ is a spectrum of severity that may be amenable to nontraditional interventions that allow affected individuals to function and accept some distortions in perception.
“What we want to do for these patients is show an improvement and ideally eliminate their dysesthesia sensations. We not only want to improve their cutaneous feelings, but also their emotional feelings,” he said.
“We want to reprogram, reduce and redirect their ‘brain talk,’ that is saying ‘this sensation on my skin must mean something horrific is going on’,” Dr. Fried said. “We want to reduce their anxiety and dread. We want to assure ongoing vigilance of organic causes. We want to enhance their sense of control.”
“Lastly, we do indeed need to regularly revisit the possibility of true infection, infestation or paraneoplastic presentation.”
This article was previously published in the Aug. 2016 edition of The Chronicle of Skin & Allergy.