In collaboration with the European Dermatology Forum (EDF) and the European Academy of Dermatology and Venereology (EADV
There is currently no standardized method for describing pruritus. Itching largely depends on external and internal changes, which may be due to a feeling of fatigue, anxiety, stress. The collection of anamnesis and a thorough examination of the patient are of fundamental importance, since they become the basis for assessing the intensity of itching, the nature, and causes of occurrence.
This guide discusses the forms, symptoms, and possible causes of itching and provides an overview of various diagnostic methods.
Read Part 1 here
Chronic itching due to medication
Almost any drug can cause itching through various pathomechanisms. Some drugs can cause an urticarial or measles-like rash that occurs along with severe itching. Moreover, drugs that cause hepatotoxicity or cholestasis, as well as drugs that cause xerosis or have phototoxic properties, can cause chronic disease in normal skin.
Medicines that may cause or maintain chronic disease (without rash):
ACE inhibitors: captopril, enalapril, lisinopril.
Antiarrhythmic drugs: amiodarone, disopyramide, flecainide.
Antibiotics: amoxicillin, ampicillin, cefotaxime, ceftriaxone, chloramphenicol, ciprofloxacin, clarithromycin, clindamycin, trimoxazole, erythromycin, gentamicin, metronidazole, minocycline, ofloxacin, penicillin, tetracycline.
Antidepressants: amitriptyline, citalopram, clomipramine, desipramine, doxepin, fluoxetine, fluvoxamine, imipramine, lithium, maprotiline, mirtazapine, nortriptyline, paroxetine, sertraline.
Antidiabetic drugs: glimepiride, metformin, tolbutamide.
Antihypertensive drugs: clonidine, doxazocin, hydralazine, methyldopa, minoxidil, prazosin, reserpine.
Anticonvulsants: carbamazepine, clonazepam, gabapentin, lamotrigine, phenobarbital, phenytoin, topiramate, valproic acid.
Anti-inflammatory drugs: acetylsalicylic acid, celecoxib, diclofenac, ibuprofen, indomethacin, ketoprofen, naproxen, piroxicam.
Angiotensin II antagonists: irbesartan, telmisartan, valsartan.
β-blockers: acebutolol, atenolol, bisoprolol, metoprolol, nadolol, pindolol, propranolol.
Bronchodilators, mucolytics, respiratory stimulants: aminophylline, doxapram, ipratropium bromide, salmeterol, terbutaline.
Calcium antagonists: amlodipine, diltiazem, felodipine, isradipine, nifedipine, nimodipine, nisoldipine, verapamil.
Diuretics: amiloride, furosemide, hydrochlorothiazide, spironolactone, triamterene.
Hormones: clomiphene, danazol, oral contraceptives, estrogens, progesterone, steroids, testosterone and its derivatives, tamoxifen.
Immunosuppressive drugs: cyclophosphamide, cyclosporine, methotrexate, mycophenolate mofetil, tacrolimus (up to 36%), thalidomide.
Lipipidemic drugs: clofibrate, fenofibrate, fluvastatin, lovastatin, pravastatin, simvastatin.
Neuroleptics: chlorpromazine, haloperidol, risperidone.
Plasma substitutes, agents affecting blood vessels: hydroxyethyl starch, pentoxifylline.
Tranquilizers: alprazolam, chlordiazepoxide, lorazepam, oxazepam, prazepam.
Uricostatics: allopurinol, colchicine, probenecid, thiopronin.
Hydroxyethyl starch, which is used to restore fluid balance, can lead to chronic generalized or localized itching.
II. Chronic itching in certain categories of patients
HZ in the elderly
There have been few studies on pruritus in the elderly. They were characterized by sampling errors and heterogeneous endpoints (pruritic skin disease or pruritus). Skin pruritus was the most common reason for doctor visits in the US Elderly Complaints Study, occurring in 29% of cases. In a study in Turkey involving 4099 elderly patients, it was found that itching was the most common skin symptom with an incidence of 11.5%. This indicator was higher in patients older than 85 years (19.5%), in addition, itching was pronounced in the winter period of the year (12.8%).
In the Thai study, pruritus was the most common skin complaint among the elderly (41%), while xerosis was a common pathology (38.9%) among 149 elderly patients. The exact mechanism of the occurrence of CKD in elderly patients has not been established. Age-related pathophysiological changes in the skin, decreased function of the stratum corneum, skin xerosis, comorbidities and polypharmacy all play a significant role in the development of chronic disease in this category of patients.
Chronic itching in pregnancy
Epidemiological studies that have examined the prevalence of chronic disease in pregnant women have not been conducted. Itching is the leading dermatological symptom in pregnant women; according to some estimates, its frequency is about 18%. Itching can be the main symptom of specific dermatosis of pregnancy, such as polymorphic dermatosis of pregnancy, pemphigoid of pregnancy, intrahepatic cholestasis of pregnancy (ICP), atopic rash in pregnancy, and can also be observed in other dermatoses that coincidentally coincided with pregnancy or preceded it.
Polymorphic dermatosis of pregnancy is one of the most common dermatoses of pregnancy and is registered in 1 out of 160 pregnant women. While pemphigoid pregnancy, polymorphic dermatosis of pregnancy and VCV usually develop in late pregnancy, atopic rash in pregnant women in 75% of cases debuts before the third trimester.
VCS is characterized by intense itching without any primary skin lesions, secondary skin lesions develop due to scratching. Pathology is more common among North American Indians in Chile (27.6%) and Bolivia (13.8%), due to ethnic predisposition, as well as nutritional factors. Now the frequency of VCV has decreased in both countries, in Chile, for example, to 14%. This pathology is more common among pregnant women of older age groups, as well as with multiple pregnancies, a history of cholestasis, as a result of taking oral contraceptives, and also in the winter season. Residents of the Scandinavian and Baltic countries are also often affected (1-2%). In Western Europe and North America, VCV occurs in 0.4-1% of pregnant women.
The use of local or systemic drugs is determined by the etiology, stage of the process, as well as the condition of the skin. Due to the possible effect on the fetus, the treatment of pruritus in pregnant women requires a balanced approach, taking into account the justification of therapy according to the severity of the underlying disease, therefore, it is necessary to choose the safest available treatment methods. In severe and generalized forms of chronic disease, it may be necessary to use systemic agents: systemic glucocorticosteroids (GCS), certain antihistamines (AHP), phototherapy (UVA).
Chronic pruritus in children
Epidemiological studies on the prevalence of chronic disease in children have not been conducted. The differential diagnosis of chronic disease in children is carried out with a number of diseases, mainly with AD. The cumulative incidence of AD in developed countries ranges from 5-22%. The German Atopic Dermatitis Intervention Study (GADIS) showed a significant correlation between pruritus intensity, AD severity, and sleep disturbances. In a Norwegian cross-sectional questionnaire survey among adults, the prevalence of pruritus was 8.8%. Itching has been associated with psychiatric disorders, gender, sociodemographic factors, asthma, rhinoconjunctivitis, and eczema. Mild to moderate itching may accompany acne.
No studies have been conducted on the systemic causes of CKD in children. It is assumed that the systemic causes of chronic disease in children are predominantly genetic or systemic diseases, such as atresia or hypoplasia of the bile ducts, familial hyperbilirubinemia syndrome, polycystic kidney disease. Drug-induced pruritus without specific skin lesions is rare in children. Drugs are most often associated with chronic disease in adults, but play a lesser role in children due to their limited use in childhood.
Regarding treatment, it must be remembered that topical treatments in children can cause intoxication as a result of the special relationship between body volume and surface area. In addition, you need to take into account the age of the child, from which you can prescribe the appropriate drug. GCS of weak (class 1, 2) and medium (class 3) strength can be prescribed to pediatric patients. Topical immunomodulators are used in children with AD and pruritus from 2 years of age, however, in some European countries, the use of, for example, pimecrolimus is allowed for children older than 3 months. Topical capsaicin is not prescribed for children under 10 years of age. Systemic drugs should be prescribed in doses adapted for children. Phototherapy is prescribed with caution, given the possible distant photolesion of the skin.
Diagnosis of chronic pruritus: overview of methods
History, examination of the patient, clinical signs of pruritus
Acquiring an anamnesis and a thorough examination of the patient are of fundamental importance during his first visit, as they become the basis for assessing the intensity of itching, the time of its onset, dynamics, nature, localization, trigger factors, as well as the reasons for the occurrence, according to the patient.
Special attention should be paid to circumstances that precede or accompany the onset of itching (eg, itching after taking a bath). You should also consider means that relieve itching, such as using a brush. This facilitates the interpretation of clinical findings, such as the absence of secondary skin lesions in the mid-back (the so-called "butterfly sign") as a result of the patient's inability to reach this area with his hands and scratch it.
It is important to establish the diseases that existed before the onset of itching, as well as allergic reactions, atopic diathesis, and the use of medications. A lot of useful information can be obtained through questionnaires.
There are no specific clinical signs of pruritic disease, but watchfulness for the following aspects of history and clinical signs may help in identifying the cause of pruritus:
- If multiple family members are affected, scabies or other parasitic diseases should be considered;
- It is important to establish a link between the occurrence of itching and certain activities. For example, pruritus that occurs during exercise may be cholinergic in nature and is common in patients with AD and mild forms of cholinergic pruritus. Itching that occurs when the skin is cooled after taking a bath should suggest an aquatic nature. Pruritus may be associated with polycythemia vera or myelodysplastic syndrome, so periodic screening for these conditions is necessary;
- generalized itching at night, accompanied by chills, fatigue, and «B» -symptoms (weight loss, fever, night sweats) increase the likelihood of Hodgkin's disease;
- somatoform pruritus rarely leads to sleep disturbances, while most other forms of it cause awakenings at night;
- seasonal itching is often presented as "winter itching", which can also be a manifestation of itching in the elderly due to the development of xerosis of the skin and asteatous eczema.
When taking anamnesis, it is always necessary to find out all medications that the patient is taking or has taken, as well as infusions and blood transfusions. Intense itching can lead to severe physiological disturbances. This fact should not be underestimated by the therapist, who is obliged to take all necessary measures. HZ may be accompanied by behavioral disorders and disruption of social and work activities.
In such cases, there is a need for psychological counseling. Chronic disease with excoriations in some cases progresses and leads to the fact that the patient causes damage to himself, which may be due to the presence of mental illness, such as hallucinatory delusions. Such patients should be examined by a psychiatrist and, if necessary, receive appropriate treatment. No psychological cause of itching can be established without consulting a psychiatrist.
Examination of patients with pruritus should include a thorough examination of the entire skin, including mucous membranes, scalp, hair, nails, anogenital area. Localization of primary and secondary skin lesions should be considered in conjunction with skin symptoms of systemic diseases. The therapeutic examination should include palpation of the liver, kidneys, spleen, and lymph nodes.
There is currently no standardized method for describing pruritus. Itching largely depends on external and internal changes, which may be due to a feeling of fatigue, anxiety, stress. The questionnaires contain information provided by the patients themselves on various aspects of chronic disease.
No standardized questionnaires exist to date, but they should provide information regarding patient prognosis, treatment prospects, and the need to define various clinical trial measures. Several questionnaires have been developed in various languages for various pruritic conditions, but the final questionnaire has not yet been developed.
Additional methods are needed to better assess various parameters of chronic disease and optimize patient management. To this end, a special group was created, which included members of the IFSI, which was supposed to determine which of the psychometric parameters of HZ are the most appropriate for its assessment.
The intensity of itching is usually assessed by scales (visual analog scale (VAS) or quantitative rating scale). When applying VAS, a 10-point scale is used, presented in the form of a graph. However, these methods often fail to take into account the frequency of itching during the day. For patients with severe pruritus of unexplained origin, it may be helpful to keep a diary to better identify symptoms.
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