Descriptors for Itch Related to Chronic Wounds

Introduction. Wound-related itch can be a source of great discomfort for patients with chronic wounds. Although itch is common among patients with chronic wounds, it is an understudied phenomenon. A greater understanding of itch is needed in order for clinicians to more effectively manage it. Objective. The purpose of this study is to identify descriptors for wound-related itch based on patient responses. Methods. Data from structured interviews of patients with chronic wounds were analyzed. Those patients who described wound-related itch were asked to rate how much various descriptors matched their itch on a scale of 0 (not at all) to 4 (to a great extent). Analysis included descriptive statistics and principal components factor analysis. Results. Fifty-six of 199 (28%) patients with wound-related itch rated descriptors, and 5 categories of descriptors were identified. A concise set of 15 descriptors of itch related to chronic wounds was defined from this. Conclusions. This list of descriptors for wound-related itch can be tested further for clinical use and for research purposes when wound-related itch is being explored. 

Wound-related itch can be a source of great discomfort for patients with chronic wounds. Although wound-related itch is common among these patients, it is an understudied phenomenon. A greater understanding is needed in order for clinicians to more effectively manage it. 

Itch (pruritus) is a subjective phenomenon, so clinicians must rely on self-reporting to understand what patients with wound-related itch are experiencing. The sensation of itch is multidimensional,¹ resulting in an extensive pool of potential descriptors for wound-related itch. Such a list of descriptors should enable clinicians and researchers to investigate wound-related itch so that this complex sensation can be more successfully defined and managed.

Numerous skin conditions result in itch. Discussion of the descriptors used for itch associated with some of these pruritic skin conditions follows, as these descriptors are potentially applicable to wound-related itch. 

Psoriasis

Psoriasis is a pruritic condition of the skin. Studies^2,3 related to psoriasis include descriptors of the itch experienced by persons with the condition. Yosipovitch et al² used a structured questionnaire to describe the prevalence and clinical characteristics of itch as experienced by 101 patients with psoriasis and extensive itch. The patients ranked 10 descriptors on a 0 (none) to 3 (severe) scale. Descriptors reported for the sensation of itch included tickling (23%), crawling (23%), and burning (17%). Pinching, stinging, and stabbing were reported by less than 5%. In addition, 4 descriptors concerning the affective dimension of itch were bothersome (53%), annoying (44%), unbearable (36%), and worrisome (18%). 

Zachariae et al³ administered questionnaires that included descriptors to 40 patients with psoriasis to explore dimensions of pruritus related to psychological symptoms and quality of life. Six sensory descriptors (crawling like ants, tickling, pinching, stabbing, stinging, and burning) and 4 affective descriptors (bothersome, annoying, unbearable, and worrisome) were ranked by patients using a 4-point Likert scale. Results confirmed the multidimensionality of pruritus. Crawling like ants, tickling, pinching, and stabbing factored as sensory descriptors of itch associated with psoriasis. Unbearable, worrisome, bothersome, and annoying factored as affective descriptors of itch associated with psoriasis.

Atopic dermatitis

Another pruritic condition is atopic dermatitis. Dawn et al⁴ conducted a study in which 304 persons with atopic dermatitis completed a web-based Characteristics of Itch Questionnaire (CIQ). The web-based CIQ included 32 descriptors assessing different aspects of the itch sensation that were rated on a 0 to 4 scale, where 0 is not at all and 4 is to a great extent. Annoying, unpleasant, bothersome, or bothering were chosen by more than 98% of participants to describe the itch they experienced. 

Acne

While acne is not usually considered a pruritic condition, Lim et al⁵ interviewed 120 patients with acne and found that 84 (70%) described itch as a common symptom. A version of the CIQ was used to collect data. Descriptors chosen for the itch sensation included tickling (68%), crawling (49%), stinging (39%), and burning (32%) as well as affective descriptors including annoying (38%), bothersome (33%), worrisome (26%), and unbearable (17%).

Descriptors of itch associated with chronic wounds have not been well described in the literature. However, several studies concerning itch associated with burns and chronic wounds will be reviewed.

Burns

Itch is associated with burns while they are acute injuries and often lasts well beyond the point of healing.⁶ Gauffin et al⁷ assessed itch associated with burns among 67 persons who were 2-years to 7-years postburn. Most of the participants regarded their itch as moderately to highly annoying (23/32) or bothersome (17/32), with a few participants describing the itch as unbearable or painful. Parnell et al⁸ conducted a pilot study that included 23 burn survivors to characterize and describe postburn pruritus. Sensory and affective dimensions of itch were explored. Stinging (74%) was the most common sensory descriptor followed by pinching (48%), burning (43%), stabbing (35%), tickling (30%), and crawling (30%). Bothersome and unbearable were both selected by 91% on the affective dimension, followed by annoying (78%) and worrisome (30%). Among persons with acute itch, 100% described it as bothersome, while 94% of persons with chronic itch described it as unbearable.

Wounds

Itch related to chronic wounds was investigated by Paul et al⁹ among 161 persons who had a history of injection drug use. They found that 74 (45.9%) patients reported itch of their legs and feet. A positive correlation was found between magnitude of itch and severity of venous disease. Persons with leg and/or foot itch also had poorer health-related quality of life than persons without itch.

Paul¹⁰ explored wound-related itch among 200 persons with wounds who were being cared for at a wound treatment center. The types of wounds included vascular (venous and arterial), neuropathic, pressure, traumatic, and others. Itch was confirmed to be a clinical concern for persons with chronic wounds and was associated with wound characteristics indicating nonhealing. In addition, Paul¹¹ compared pain and itch as reported by persons with chronic wounds and found that wound-related itch more typically was described around the wound, while wound-related pain was more typically described within the wound. Descriptors of wound-related itch were not discussed.

A gap in the literature concerning descriptors of wound-related itch has been identified, necessitating further study. Knowledge of such descriptors would enable assessment and management of itch related to chronic wounds. Therefore, the purpose of this study is to identify descriptors for wound-related itch based on patient responses.

This study involved secondary analysis of data that were collected to describe itch as it occurs with chronic wounds. The study by Paul¹⁰ was conducted at a wound treatment center affiliated with a large teaching hospital in the Midwest. The sample consisted of 200 individuals whose nonhealing wounds were being cared for at the wound treatment center. Inclusion criteria required participants to have an open wound, be ≥ 18 years of age, and be able to speak and understand English. Exclusion criteria included pregnancy, closed surgical wounds, rash in the area of the wound, or pruritic skin condition involving more than 20% of total body surface area.   

Participants were interviewed by the researcher who asked them about their wound-related itch. Classification of each patient as itcher or non-itcher was based on the participant’s responses to questions regarding the presence of itch within and/or around the wound. Participants were asked questions regarding the location of their itch and were asked to provide a rating of the itch intensity from 0 (none) to 10 (unbearable itching) within the wound and on the skin around the wound. 

Participants with itch in or around the wound (itchers) were asked to rate 45 descriptors of wound-related itch. Participants also were asked to rate how much various descriptors matched their itch with response options of 0 (not at all), 1 (to a minimal extent), 2 (to a mild extent), 3 (to a moderate extent), and 4 (to a great extent). Descriptors rated were part of the CIQ.³ The CIQ was developed from the Eppendorf Itch Questionnaire¹¹ and includes descriptors based on the widely used and tested McGill Pain Questionnaire.^3,12 The CIQ has demonstrated a Cronbach α coefficient of 0.9 and test-retest reliability of 0.8.³ Permission to use the CIQ was obtained from Dr. Yosipovitch.

Analysis included descriptive statistics (ie, frequencies and means) and inferential statistics (principal components factor analysis). Because each of the 45 descriptors of itch were analyzed, there was a probability of finding significance simply by chance. To account for this, the P values would have to be very low (eg, for α = .05, P value would have to be .00125 to consider a finding significant). Principal components factor analysis with varimax rotation was used, with selection based on Eigenvalues > 1. Reliability analysis was done using Cronbach’s α for each category of descriptors. SPSS Version 24 (IBM Corp, Armonk, NY) was used for data analysis.

The study was approved by the Beaumont Hospital Commission on Nursing Scholarship and Research and the Human Investigation Committee (Royal Oak, MI) prior to data collection as well as Wayne State University’s Institutional Review Board (Detroit, MI).

Sample characteristics

In this study, 199 participants were included, with 1 participant’s data excluded because of missing data. Of the 199 participants, 112 were male (56%), 170 were Caucasian (84%), and 95 (48%) were married (Table 1). The age range of the participants was 21 to 98 years (mean, 67). Chronic wounds included venous ulcers (n = 31), arterial ulcers (n = 23), diabetic/neuropathic ulcers (n = 31), pressure ulcers (n = 33), traumatic injuries (n = 37), and other types of wounds, including wounds of (3) mixed or (38) unknown etiology. Of the participants, 28.1% (56/199) were classified as having itch (itchers) and 71.9% (143/199) were classified as non-itchers. Most of the wounds with itch were venous in nature, on the patients’ lower extremities, and were 1 month to 1 year in duration. Wound parameters (type, location, and age) are provided in Table 2.

Descriptors as rated by itchers

Descriptors with the highest mean scores were itching (mean, 3.47; standard deviation [SD], 1.03), annoying (mean, 2.85; SD, 1.58), and bothersome (mean, 2.60; SD, 1.68). The mean scores for the top 12 itch descriptors as rated by the 56 itchers are provided in Table 3. A cut-off mean score of 1.55 allowed for a concise list with mean scores above the minimal extent range.  

Principal components factor analysis

Principal components factor analysis was conducted for each itch descriptor. Results revealed a 10-factor solution that accounted for 87.6% of the total variance. Of those 10 factors, 5 appeared to group together in a meaningful way based on the factor loading results. Those 5 factors (categories) were named based on commonalities between descriptors in each group. The itch descriptors had a factor structure with 2 primary factors (affective and sensory) emerging. The following descriptors all loaded high for the “affective” category: unbearable, terrible, awful, torturing, uncontrollable, insistent, bothersome, dreadful, and unmanageable. The following descriptors all loaded high for the “sensory” category: more when cold, burning, throbbing, stinging, pulsating, penetrating, inflaming, painful, severe, hurting, and stubborn. Other categories that emerged were “life-limiting” (annoying, bothering, unpleasant, oppressive, tiresome), “prickly sensation” (pricking, prickling, ant-like, pinprick-like, restricting my life), and “heat sensation” (warm, hot, like sunburn). The rotated factor matrix of highly loading itch descriptors is provided in Table 4. Some of the 45 original descriptors did not load high in those 5 factors (tickling, mosquito-bite-like, more when warm, disturbing my sleep, tingling, comes in waves, acute), and still other descriptors did not load high on any factors at all (sharp, disgusting, my only desire: no itch, tiring, itching). 

Reliability analysis

Reliability analyses were conducted for the affective, sensory, life-limiting, prickly-sensation, and heat sensation categories with the goal of developing these groupings for future research (Table 4). Desirable values for Cronbach’s α > 0.80 indicated a high degree of internal consistency among the items. None of the items, if deleted from any of the 5 categories, showed significant gains in reliability.  

Results of this study indicate that some of the descriptors that were rated highest by persons with chronic wounds are consistent with descriptors used for itch associated with other origins as described in the literature. Bothersome and annoying were highly rated descriptors of wound-related itch and have been used to describe itch related to psoriasis,^2,3 atopic dermatitis,⁴ and burns.^7,8 Although worrisome was not included in the version of the CIQ used for the present study, it has been used to describe itch associated with atopic dermatitis⁴ and burns⁸ and was mentioned anecdotally by several persons with wound-related itch. Unbearable is a descriptor for itch from several origins including psoriasis,^2,3 acne,⁵ and burns.^7,8

Nine of the 12 descriptors that received the highest ratings by persons with wound-related itch loaded high on 1 of 3 factors: affective, sensory, or life-limiting. The affective and sensory categories are consistent with the categories in the instruments from which the CIQ was developed, namely the Eppendorf Itch Questionnaire.⁴ The Eppendorf Itch Questionnaire was designed after the McGill Pain Questionnaire, which also has affective and sensory items.^12,13 Of the 12 most highly rated descriptors, those that loaded highly in the affective category included bothersome, awful, insistent, and torturing. Severe and stubborn loaded highly in the sensory category with other descriptors that also could be used to describe painful sensations. Those that loaded highly in the life-limiting category included annoying, bothering, and unpleasant. Disturbing my sleep loaded highest under the 10th factor, which was not named. Itching and my only desire: no itch did not load highly in any category. 

The final list includes 15 descriptors for wound-related itch (Table 5). Ten of the top-rated 12 descriptors of wound-related itch were included in the list: bothersome (but not bothering), awful, and insistent, which represent the affective category; severe and stubborn, which represent the sensory category; and annoying and unpleasant, which represent the life-limiting category. Disturbing my sleep and disgusting did not factor into any of the 5 categories but were rated highly by persons with wound-related itch and may be specific to the sensation. My only desire: no itch (but not itching) was included as it speaks to the intensity and urgency of the itch sensation. Bothering is redundant with bothersome, and itching is redundant with the sensation itself, so those descriptors were not included in the final list. 

Five descriptors were added to the final list despite not being found in the top-rated 12. Mean ratings were considered (Table 4). Prickling was included from the prickly sensation category and warm was included from the heat sensation category, so descriptors from the 5 factor-loading categories are represented in the final list. Worrisome, unbearable, and uncontrollable were included because they represent other concerns. Worrisome and unbearable were mentioned in the literature related to other origins of itch.^2,3,5,7,8 The idea that wound-related itch causes worry points to the need to identify the meaning and significance of wound-related itch, so worrisome was included. Unbearable, which also scored high in the affective category, speaks to the distress that is caused by wound-related itch. Uncontrollable scored high in the affective category and points to the need for patients with wounds to have options for treating wound-related itch. 

In this study, 15 descriptors of wound-related itch were identified from a list of 45 descriptors. Categories of descriptors of wound-related itch were described as affective, sensory, life-limiting, prickly sensation, and heat sensation. The 15 descriptors should be further tested in order to capture the experience of wound-related itch and more accurate articulation of the sensation. 

The major limitation of this study was that data were collected by 1 investigator at 1 wound treatment center. In addition, participants’ descriptions of itch may not be generalizable to all patients with wound-related itch. 

The purpose of this study was to identify descriptors for wound-related itch, and a list of 15 descriptors for wound-related itch was identified. Descriptors for wound-related itch were factored into 5 categories (affective, sensory, life-limiting, prickly sensation, and heat sensation) that can be used to describe the scope of wound-related itch. This analysis defines a concise list of 15 descriptors to capture the sensation of wound-related itch. This list of wound-related itch descriptors should be tested further for clinical use and research purposes when wound-related itch is being explored.

Affiliation: Oakland University School of Nursing, Rochester, MI 

Correspondence: Julia Paul, PhD, RN, ACNS-BC, CCRN, CWS, NP, Assistant Professor, Oakland University School of Nursing, 3044 Human Health Building, 433 Meadow Brook Road, Rochester, MI 48309-4452; jcpaul@oakland.edu

Disclosure: The author discloses no financial or other conflicts of interest.

The author would like to thank Patrick Doyle, PhD, for his statistical work in the preparation of this manuscript.