Pruritus

DIAGNOSIS:

Symptoms:

Itching is the particular sensation causing the need to scratch. It may be diffuse or focal, affecting the skin and mucous half.

It may sound a major way on the quality of life.

The examination, diagnosis of pruritus. It should also seek the notion of triggering factors, possible outbreaks and their rhythm. Patient history, the concept of drug taking, pruritus in the entourage are important. General signs are to be searched.

Clinical examination:

Clinical examination should be complete. To the skin, it is necessary particularly search for the existence of skin lesions orienting toward a particular dermatosis or due to scratching.

Scratching are:

– Excoriations and linear streaks;

– Skin thickening, lichenification, pigmentation if the itching is old;

– Nails polished and shiny hands;

– Worn and broken hairs, presence of popped zones (pubis, eyebrows).

The diagnosis is often made by taking and clinical examination. Tests may be requested first line (Box 1) possibly as clinically without obvious cause.

Box 1. Summary of first-line without obvious cause itching

Interview and clinical examination +
Complete blood count (CBC) platelets
Serum electrolytes, urea, creatinine
Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin and conjugated
HIV status
Thyroid stimulating hormone (TSH)
X-ray chest
Abdominal ultrasound

Pruritus treatment is mostly that of its cause.

PRURITUS DIFFUS:

Dermatoses:

Skin lesions suggestive of dermatitis are listed in Box 2.

Box 2. Key dermatosis with specifi c lesions
Allergic contact dermatitis (contact dermatitis), caustic or irritant
Atopic dermatitis
Urticaria and dermographism
Ectoparasites: scabies, pediculosis body
Insect Bites
Psoriasis
Lichen planus
Bullous pemphigoid
T epidermotropic cutaneous lymphomas (mycosis fungoides and Sezary syndrome)
Dermatophytoses

Urticaria:

Erythematous papules, edematous, fleeting, mobile and migratory evoke urticaria (see Hives).

A streak induced urticarial scratching is suggestive of dermographism. The treatment is that hives.

Eczema:

Érythématovésiculeuses lesions reminiscent of eczema, which can be related to atopic dermatitis or contact.

Preexisting lesions may eczématiser (cf. vesicles).

Gale:

Itching at night dominance, reaching the front face of the wrists, the interdigital spaces, buttocks and nipples evokes an itch (pruritus see ectoparasites). We must also think about pediculosis before a subject to the conditions of poor hygiene (see itch ectoparasites).

Bullous disorders:

Pruritus may precede the onset of lesions of bullous pemphigoid (urticarial plaques, bubbles) in the elderly, or dermatitis herpetiformis (vésiculobulles) in younger patients.

Cutaneous lymphoma epidermotropic:

Érythématosquameux of cupboards, chronic, although limited, itchy, especially in the elderly should evoke a cutaneous lymphoma epidermotropic. The lesions infiltrate with time.

The patient should be referred to a specialist.

Histology is often behind the clinic.

Treatment may involve topical Caryolysine® or Mustargen®, to corticosteroids or interferon-α.

Psoriasis:

Non pruritic dermatoses may be deemed to scratch, such as psoriasis.

Lichen planus:

Papular lesions, although limited, purple or brownish color, covered surface whitish streaks evoke lichen planus.

The topography is suggestive: anterior wrists, forearms, elbows, knees and lower back.

Systemic mastocytosis:

Systemic mastocytosis is a rare disorder characterized clinically by the presence of multiple brownish papules with urticaria friction (Darier’s sign) and combining readily with the occurrence of flushes (cf. flushes).

Irritants:

Pruritus, erythema, papules, bubbles, following the application of an external agent sign pruritus by irritants.

It can be glass wool, plant, soaps, sufficiently rinsed cleansing milks, detergent (especially fabric softeners, especially atopic), a bath in the sea.

Variations of temperature and humidity:

It is related to the mismatch of skin hydration. It is seen especially in atopic subjects, aged transplanted organ (especially in blacks).

It can also be triggered by contact with water, regardless of temperature (Aquagenic pruritus). We must think about blood diseases (polycythemia, hypereosinophilic syndrome, lymphoblastic leukemia, myelodysplasia).

The anti-H1 antihistamines (Zyrtec® 1 cp / d) and alkalinization of the bath water (sodium bicarbonate 25 to 200 g in the bath) is useful.

Psychogenic pruritus:

Psychogenic pruritus is a diagnosis of exclusion.

The examination and clinical examination noted a significant isolation, depressive syndrome or delusions of parasitism.

Treatment is with anti-H1 (Zyrtec®, 1 cp / d) or doxepin, associated with emollients (cf. symptomatic treatment) and psychological support.

In the elderly:

Senile pruritus is a diagnosis of exclusion. It is particularly important to eliminate bullous pemphigoid debutante, a scab (especially if the subject lives in institutions), lymphoma or drug drug eruption. Itching is triggered by various stimuli (heat, wool, etc.) or spontaneous.

Treatment is symptomatic, difficult and disappointing.

Internally pruritus (pruritus sine materia):

The presence of only scratching lesions with no triggering circumstances, drug taking and psychological disorders evoke internally itching (pruritus sine materia). They are rare, but should be systematically sought (Box 3).

Box 3. Major systemic causes of pruritus
Insuffi chronic renal failure
Cholestasis
Pharmaceuticals
Hematologic malignancies: Hodgkin, vera HIV disease
Dysthyroïdies
Parasites (roundworms and toxocariasis)
Iron deficiency

Renal failure:

This is subject suffering from chronic renal failure. They are amenable to treatment, often disabling, sometimes aggravated by dialysis.

Several treatments have been proposed, apart from symptomatic treatment (see Treatment), but kidney transplantation is the best option. Among the treatments used in town by general include cholestyramine (Questran)orally at a dose of 3 sachets / day oral activated charcoal (6 g / d). Thalidomide (50 mg / day and 100 mg / day under cover of a lack of pregnancy and effective contraception), phototherapy, Narcan® are the responsibility of the hospital specialist.

Cholestasis:

Gall retention may cause itching, whether or not jaundice. Pruritus is often greater at night.

There is often a skin hyperpigmentation respecting the mid back region. A progressive jaundice with impaired general condition and pruritus, evokes a cancer of the bile ducts, pancreas or liver.

The main causes are viral hepatitis, drug, cholestasis of pregnancy, primary biliary cirrhosis, primary sclerosing cholangitis. The alcoholic cirrhosis and hemochromatosis are not usually causes pruritus.

Treatment is primarily that of the cause. Several treatments may be tried: cholestyramine (Questran) three sachets / day po, cons-indicated in cases of complete obstruction of the bile ducts.

The improvement is achieved in 3 to 4 days. Some propose including naltrexone (Nalorex® 50 mg / d), phenobarbital, rifampin.

Endocrinopathy:

This is hypo- and hyperthyroidism (cf. goiter and thyroid nodule). Pruritus hyperthyroidism is seen especially in Basedow’s disease; in hypothyroidism, it is linked to skin dryness. Jaundice associated with flushing, besides the already mentioned mastocytosis, should suggest a carcinoid tumor (see Flushes).

Contact with water, especially hot:

We must mention polycythemia vera (signs of hyperviscosity, polycythemia with hematocrit> 55% presence of the mutation JAK II, total cell mass measured by high isotopes, rich marrow with predominant hypertrophy of erythroid, and pushes low EPO spontaneous erythroid progenitors).

Treatment may use aspirin or PUVA.

In a young adult:

In addition to HIV, we must always think of Hodgkin’s disease, especially since there are palpable lymphadenopathy (cervical ++), night sweats and impaired general condition.

Non-Hodgkin lymphomas give the same type of itching in the older patient.

Itching is a poor prognosis if it is intense. It may precede other manifestations of the disease and be revealing. It can also be a harbinger of a relapse in a patient treated.

Symptomatic treatments are often ineffective antipruritic: the best treatment of pruritus is here that of the blood disease.

Recall also that pruritus can be indicative of iron deficiency anemia, myeloma, Waldenstrom’s a disease and monoclonal gammopathy of undetermined significance.

HIV:

Before a chronic pruritus occurring in young patients, we must always think about HIV, especially that there are risk factors (intravenous drug abuse, multiple unprotected sexual intercourse, homosexuality, etc.). Pruritus associated with HIV may be indicative of progression to AIDS.

Apart from scratching, you can see papules.

Treatment is difficult; Further systematic measures, we must have recourse to a specialist who can provide phototherapy or thalidomide.

Itching of ectoparasites:

Gale:

* Diagnosis:

Pruritus interdigital spaces, wrists, nipples, buttocks with excoriated lesions at night upsurge should suggest scabies, especially since the topic is older and is institutionalized or living in difficult socio-economic conditions (SDF ). The review should look furrows and vesicles (blisters beaded) For own people, the lesions can be summarized pruritic papule glans of the sleeve (canker scabious).

* Treatment:

The treatment is local first:

– The first day, undressing, taking a

hot, soapy shower then brush with benzyl benzoate (Ascabiol®) on the body except the face, damp skin.

Wear clean clothes and change the bed sheets Put dirty clothes and bed sheets in an airtight bag and spray by Spregal® spray (cons-indications: asthma and pregnant women). The other possibility is to wash at 60 °. Do not wash for 24 hours.

– The second day, take a warm, soapy shower again. Put on clean clothing.

The enclosure shall be examined and treated systematically.

Itching may persist after treatment: it can be treated with emollient creams kind Eurax® one application per day; the topical antiscabieux are irritating and should not be used indiscriminately.

Recall that scabies is a sexually transmitted disease and that HIV status should be offered in younger patients.

Outbreak or in an institution, treatment by taking a single dose of three tablets Ivermectine® (200 micrograms per kilo) is also possible. Efficiency is visible after 4 weeks.

Pediculosis corporis:

Pruritus with excoriations scattered on the trunk and the root of the members in a subject in difficult socio-economic conditions can be related to body lice. Lice circulates on the body to feed and live in clothes. The diagnosis is made by visualization of parasites on the body or clothing. Recall that the body louse can transmit rickettsial (trench fever, typhus) and borreliosis (relapsing fever).

Disinfect the machine body and bedding.

It may further apply a malathion-based lotion for 12 hours.

Pediculosis of head:

Itching of the scalp, diffuse or retroauricular predominance extending to the neck and upper back (in cape), can be related to head lice. The disease is rare in adults; children of school age are most often affected. There are excoriations of the scalp, neck with regional lymphadenopathy; the diagnosis is certain if nits are visible (which is rarely the case for adult lice).

Treatment is based on applying a lotion containing malathion (Prioderm®) for 12 hours; hair should then be shampooed and combed with water and vinegar to bring down slow. Treatment should be repeated every eight days until no nits. All contacts should be treated subjects.

Phthiriasis:

Itching pubic hair evokes phthiriasis (crabs). This is a sexually transmitted disease. Slow and adults (gray spot near the pile of hole) are hardly visible. Perianal hair, armpit, chest and even the eyebrows may be affected. The classic slate abdominal spots are extremely rare.

Treatment is based on the same terms as the head lice (treat all pubic hair areas, trunk and thighs).

At an African topic or returning from Africa:

Pruritus in about an African or returning from Africa evokes, in addition to HIV, systemic parasitic diseases, especially that there is a blood eosinophilia. The presence of papules and vesicles evokes onchocerciasis. We must also think about trypanosomiasis, bilharzia and fluke.

Ciguatera poisoning:

Pruritus after ingestion of tropical fish is related to the ingestion of ciguatera (toxin).

In pregnant women:

Pruritus in pregnant women, in addition to causes not of pregnancy, should suggest a pregnancy itching, pemphigoid of pregnancy or a polymorphic dermatosis of pregnancy (see rash during pregnancy).

Of medication:

Medication must be systematically recorded, even in the absence of skin lesions.

Treatment is stopping the drug due and classic symptomatic treatment.

Solid cancer:

The solid cancer mainly concerns cancer causing blockage of the bile ducts.

Very rarely, it is indicative of a deep cancer (colon, stomach, prostate, lung, brain). Pruritus disappears after the treatment of cancer.

Itching of the nose wing evokes a brain tumor.

Hypercalcemia:

Pruritus associated with hypercalcemia suggests hyperparathyroidism (cf. hypercalcemia).

Hypereosinophilia:

Pruritus associated with eosinophilia suggests a parasitic disease or blood disease (see hypereosinophilia).

LOCALIZED pruritus:

We must think of the elective localization of dermatitis.

Insect bites:

The diagnosis of insect bites is obvious.

Lesions may be urticarial sometimes centered by a purpuric and necrotic spot.

Treatment is symptomatic with antihistamines

Zyrtec® type 1 cp / d application if necessary Diprosone® kind of topical steroids or Tridésonit®.

Dermatophytosis and candidiasis:

Specific lesions orient the diagnosis (see intertrigo).

Itching of the scalp and neck:

We must think about head lice (see below), but also an intolerance to hair and cosmetics, with a simple dandruff, psoriasis and seborrheic dermatitis (see Alopecia).

Lichenification neck evokes a neurodermatitis.

Notalgia paresthetica:

Pruritus localized to an elective area of the upper back, below the tip of the scapula, no visible skin lesion, evokes a paraesthetica notalgia.

The etiology is unknown.

Treatment is difficult. We can try capsaicin topical (Kamol® balm, 2-3 applications

per day), local anesthetics like Emla (a patch Emla topically) or antidepressants Prozac Deroxat® type or 1 tablet / day.

Other causes:

Allergy to cosmetics:

A facial pruritus in women is seeking an allergy to cosmetics.

Zona:

Pruritus may be sequelae of herpes zoster.

Pruritus brachioradial:

The brachioradialis pruritus is pruritus located at the bending zone of the elbow sunlight. It is related to sun exposure. In addition to the cessation of exposure, it is necessary to implement the symptomatic treatment.

Unilateral pruritus:

A unilateral pruritus without skin lesion evokes the rare possibility of a cerebrovascular accident (CVA) or brain abscess.

TREATMENT:

It is based primarily etiological treatment. Symptomatic treatment is local and general.

Aggravating factors are researched and treated (eg softeners, antiseptics alcoholics, scented soaps, tight clothing, etc.). Nails should be cut short.

Local treatment:

Starch, soap surgras, emollients:

Baths with added starch may be proposed (Aveeno®: 3 pinches in the bath).

Soaps surgras or syndets (soap without soap) are also useful: Soap from Rogé Surgras® Cavaillès®, Lipikar Syndet®.

Emollients may be used: Cold Cream®, Lipikar Baume®, 1-2 applications per day.

Corticosteroids:

Topical corticosteroids are often helpful on excoriations. Recall that they are against-indicated in infectious dermatoses.

On the body, one can use a topical corticosteroid with high activity (class 3) (Diprosone® Betnéval® or cream) on a clean, dry skin in decreasing doses. The number of tubes should be noted on the order.

Example decay: 1 application per day for 7 days, then every other day for 7 days and then twice per week for 7 days and then stopped.

On the face, topical corticosteroids should be avoided whenever possible, especially on the eyelids (risk of glaucoma). A dermocorticoid of moderate activity (class 2) Type Tridésonit® for a week to 10 days, in decreasing doses, can be proposed: 1 application per day for 3 days, then every other day for 4 days, and stop.