Does Itching Disturb Your Regular Activities?

Nowadays, itching is a major problem or symptom of most allergic, systemic or fungal diseases. Four out of 10 people have had some type of itching problem of the skin in their routine life. Severe itching disturbs the day-to-day activities of a human being.

What Is Itching?

Itching is defined as some type of unpleasant sensation that increases the desire to scratch to relieve the feeling.

It is also referred to as pruritus or urticaria.

If itching is present for more than 6 weeks, it will be considered severe or chronic and needs careful evaluation and treatment.

At times itching is beneficial because skin triggers itch and serves as a protection for our body to remove foreign particles from the skin. But this will be for a few seconds only.

Who Are Most Likely to Get Affected?

People of any age can be affected.

Children are less affected than adults.

What Is the Pathophysiology of Chronic Itching?

There are many factors that trigger itching.

Itching may be localized or generalized.

Many physical, external, and internal stimuli activate itching receptors and produce severe itch.

Receptor for activation of itching is free nerve endings of nonmyelinated C-type nerve fibers that are located in the superficial layer of skin (epidermis).

Patients with severe itching are highly sensitive to histamine and serve as internal stimuli.

Other responsible receptors for severe itching are G protein receptors, histamine H4 receptor, brain-derived neurotrophic factor, and neurotrophins nerve growth factor.

Keratinocytes:

Keratinocytes provide immunity against severe itching.

It provides protection against physical, environmental, and chemical stimuli.

It produces itching in the skin by means of the removal of foreign particles from the skin by scratching.

Furthermore, sensory nerves, along with epidermal keratinocytes in the skin, also enhance itching sensation.

When keratinocytes are activated, they will release inflammatory and pruritic substances.

Keratinocytes have both functions, activation, and inhibition of itch.

Mast Cells:

The most common mast cell mediator responsible for itching is histamine.

Mast cells contain large numbers of histamine.

When mast cells are activated, they release histamine in the surrounding area and activate H1, H3, and H4 receptors. Blockage of these receptors causes a reduction in itching and inflammation.

Mast cells of psoriasis contain interleukin-31, which is a potent pruritogenic substance.

Cells that activate mast cells in pruritic diseases are neutrophils such as NT-3.

Eosinophils:

In chronic skin diseases, there is the presence of increased cellular infiltration of eosinophils. They are found in the vicinity of nerves.

Various neuropeptides and other cytokines cause activation of eosinophil for itching.

What Is the Etiology for Chronic Itching?

Different diseases such as inflammatory skin diseases, metabolic diseases, liver and kidney diseases, lymphoproliferative diseases, and myeloproliferative diseases are the cause of severe itching.

Some dermatological causes of itching are:

Electrostatic charges.

Fiberglass and other irritants.

Plaster of Paris casts.

The systemic diseases associated with itching are:

Chronic renal failure.

Hepatic Cholestasis:

How Is Severe Itching Diagnosed?

Present History – Evaluation of underlying disease, time of onset, the severity of itching, and duration of itching should be asked to the patient.

Itching History – Aggravating factor, relieving factor, and severity scale should be noted.

Associated Factors – Lymph node enlargement, tumor, chronic skin diseases, fungal infection, ringworm infection, urticaria, etc., should be diagnosed.

Skin Examination – Size of the patch, affected area, depth of patch, shape of the patch, presence of scaling border should be evaluated.

Sign of Itching – Dryness of skin, pigmentary changes of the skin, skin color changes, redness, swelling of the skin, etc., are looked at.

On Palpation – It is important to note any warmth on palpation.

Also, the doctor will look for associated sensations such as burning, irritation, and dull ache.

Other clinical procedures to evaluate skin diseases are skin biopsy, skin allergy test, blood test, urine analysis, CT (computed tomography) scan, and brain MRI for detection of tumor (magnetic resonance imaging).

How Is Severe Itching Treated?

Precautionary Measures:

The affected area should be washed with an antiseptic solution followed by the application of moisturizing lotion to eliminate dry skin.

During summer, increased fungus growth causes severe itching due to sweat, so the skin should be clean to eliminate this problem.

Some internal or external stimuli should be avoided, such as cold weather.

Application of antifungal dusting powder such as Clotrimazole over an affected area gives a beneficial effect. It should be applied after bathing, swimming, etc.

Innerwear should be changed every day or twice a day.

Loose-fitting clothes, preferably cotton clothes, helps to eliminate sweat problems that aggravate severe itching.

Diabetes is a leading problem of severe itching due to low immunity, and it will increase the chances of fungal infection. Hence glucose levels must be within normal limits.

Exchange of clothes with others should be avoided. It will increase the chance of ringworm infection.

Sweating or perspiration should be prevented as much as possible. And it is achieved by the application of antiperspirant skin-friendly deodorant.

Nowadays, some washes are available for the treatment of severe itching in the genital area of the female. It maintains and balances the normal pH.

Walking barefoot also aggravates the itching problem. So, wearing sandals is beneficial.

Blood or other laboratory investigations should be evaluated because some sexually transmitted diseases will aggravate severe itching.

Local Approach:

Treatment should be established for the underlying cause of severe itching.

Temporary relief should be achieved by Polidocanol or Menthol as it gives a soothing and cooling effect over the affected part.

Application of topical corticosteroids and different emollients will help to eliminate the itching problem.

Supportive therapy for sleep disturbances, antidepressants, and sedatives are given, and for chronic erosive scratching, local corticosteroid administration is done.

Treatment of atopic dermatitis, chronic eczema, and genital fungal infection with a calcineurin inhibitor and topical cannabinoid is necessary.

The primary treatment for chronic pruritus and chronic urticaria are non-sedating H1 antihistamines, as it decreases degradation and release of pruritogenic mediators by mast cells and increases antipruritic effect.

The use of lubricants such as oil, humectants like urea also helps with itching.

Use cooling agents like menthol and camphor for topical application.

Systemic Approach:

The aim of the systemic approach is to target the central nervous system to eliminate itching.

Treatment with anticonvulsants such as Gabapentin and Pregabalin are also available for chronic itch.

Antipruritic drugs such as agonists (Naltrexone) or antagonists of the opioid system will act centrally and give relief.

Severe itching in refractory hemodialysis patients is treated by using a k-receptor agonist, Nalfurafine.

Selective serotonin reuptake inhibitors (SSRIs), Paroxetine, and Sertraline are useful in severe itching in patients with polycythemia vera, somatoform pruritus, paraneoplastic pruritus, and cholestatic pruritus.

Idiopathic pruritus, cholestasis, uremia and neoplasm-induced pruritus are treated with Mirtazapine.

In severe cases of pruritus, tricyclic antidepressants like Doxepin are used.

Use antifungal agents in the treatment of fungal infections such as Amphotericin B, Ketoconazole, Miconazole, Fluconazole, Voriconazole, Itraconazole, Posaconazole, Echinocandins such as Caspofungin, Anidulafungin, and Micafungin.

Use Griseofulvin for ringworm infection.

Use Terbinafine for onychomycosis (fungal infection of the nail) and for ringworm infection.

Other topical or systemic therapy that gives permanent relief from itching includes treatment with Capsaicin, Calcineurin inhibitor, UV therapy, immunotherapy, immunosuppressive therapy, etc.

This content was originally published here.

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