Itching without rash

Such a common symptom as skin itching usually accompanies a rash. However, there is also itching without rashes, due to a fairly wide range of pathological conditions and systemic diseases.

In scale, pruritus without visible skin changes can be generalized (common) or localized, and in duration - acute, intermittent or chronic.

Causes of the itching without rash

Itching without rashes - pruritus sine materia (from Latin - itching without matter), that is, without primary skin lesions - as a rule, has nothing to do with skin diseases, and in dermatology is a diagnosis of exclusion.

The simplest case - itching of the hands without rashes - due to  dry skin of the hands . But it should be borne in mind that dry skin (xerosis) can provoke disruption of the thyroid gland and metabolism.

According to experts, itching of the skin on the hands and throughout the body can for some time outpace the appearance of a rash, for example, when infected with intradermal scabies itch (Sarcoptes scabiei) and the development of an infection such as  scabies ; with herpes zoster - when burning, itching of the lower back without rashes and pain occur a few days before the Varizella zoster virus (VZV) manifests itself as a typical pustular rash. [1]

Among the most probable experts consider such reasons for the appearance of pruritus sine materia:

• the presence of diabetes;
• kidney disease leading to terminal failure (especially in patients on dialysis);
• hepatitis,  primary biliary cirrhosis ,  [2]primary sclerosing cholangitis,  [3]and liver damage by parasites such as Giardia intestinalis,  [4] opisthorchis felineus (cat fluke)  [5]or fasciola (Fasciola hepatica). [6]By the way, if the itching of the skin in a child without rashes, then the first thing that can be suspected is the presence of helminths.

Itching that is not accompanied by a rash is on the list of symptoms:

• pancreatic diseases, including cancer;
• problems with the thyroid gland - thyrotoxicosis, hyperthyroidism;
• iron deficiency in the body (iron deficiency anemia) - provokes itching of the face without rashes;
• refractory anemia or  myelodysplastic syndrome ; [7]
• erythremia or  true polycythemiaassociated with benign proliferation of blood cells; [8]
• HIV infection.

According to oncologists, the first signs of cancerous degeneration of tissues of various organs can be manifested by itching in the region of regional lymph nodes. Such itching is called paraneoplastic and is noted in leukemia, lymphomas, plasmacytoma, as well as cancer of the gallbladder and liver, prostate carcinoma, lung adenocarcinoma and carcinoid syndrome.

Neurogenic or neuropathic is called:

• itching of the hands and feet without rashes in  multiple sclerosis ; [9]
• itching of the upper chest and itching of the back without rashes with paresthetic notalgia (notalgia paresthetica) - a hereditary form of chronic sensory neuropathy; [10]
• itching of the lower back without rashes in cases of damage to the nerve roots of the lumbar spinal cord in diseases of the spine.

With stress, depression and mental disorders (psychosis,  obsessive-compulsive disorder , schizophrenia), itching without any morphological changes in the skin is considered to be psychogenic or psychosomatic.

Itching without visible damage to the skin, caused by contact with water, is called aquagenic.

In pregnant women, due to stretching of the skin and increased levels of hormones, severe itching of the skin on the abdomen without rashes occurs; more information in the article -  Itching during pregnancy .

In addition, itching of the skin without redness and rashes can also be caused by drugs: opiates, statins, anticoagulants, some antihypertensive drugs, antimalarial drugs, antibiotics, oral contraceptives. And itching of the face without rashes can be the result of taking niacin (vitamin B3 or nicotinic acid).

Risk factors

Risk factors for the appearance of physiological itching without any elements of a rash (in the form of papules, vesicles, macules or pustules) are  dry skin of the body , which may be associated with the use of too hot water for bathing, hereditary skin characteristics, age-related xerosis.

There is a widespread generalized pruritus without rash in the elderly.

Risk factors for pathological pruritus sine materia are endocrine, hematological, systemic, neurological diseases and mental conditions in which this symptom appears.

Pathogenesis

The general mechanism of pruritus is discussed in the publication -  Pathogenesis of itching of the skin .

In addition to age-related physiological changes in the skin - a deterioration in its hydration and a decrease in sebum production, itching all over the body without rashes after 65 years of age is associated with age-related sensory neuropathy, changes in the immune system, and often unjustified intake of several drugs (polypharmacy).

Itchy skin without rash often affects the lower extremities of diabetic patients, and its pathogenesis is associated with prolonged hyperglycemia and poor circulation. Itching is often a symptom of damage to the nerve fibers of the skin - diabetic polyneuropathy. Read more -  Itching in type 1 and type 2 diabetes .

Itching without rash during pregnancy or pruritus gravidarum is caused by elevated serum bile acids due to intrahepatic  cholestasis  at the end of the second or third trimester (called cholestatic hepatosis of pregnancy). Why it occurs in some pregnant women, causing itching of the skin of the extremities and yellowness of the skin of the body, is not fully understood. This condition can adversely affect the outcome of pregnancy.

Paraneoplastic pruritus is the result of the activity of pro-inflammatory cytokines released by immune cells in response to malignant transformation of cells, and substances that are produced by tumor cells and can act both directly on nerve endings and cause the release of histamine. And with pancreatic cancer (especially if the tumor has formed in its head), obstruction of the bile ducts, stagnation of bile and subsequent accumulation of bile salts in the skin, which provokes itching, often occur. Other symptoms may include jaundice, abdominal pain, ascites, discoloration of the stool.

In some cases, itching without a rash—especially aquatic—may appear months before a cancer diagnosis such as non-small cell lung cancer or lymphoma is diagnosed. After contact with water, intense pruritis always begins in polycythemia.

The mechanism of psychogenic pruritus in patients with CNS disorders and psychiatric problems is due to acetylcholine activation of the sensory area of the anterior cerebral cortex, accessory motor areas, and lower parietal lobe.

And itching during stress - with the effect of adrenaline on β2-adrenergic receptors - is mediated by activation of the hypothalamic-pituitary system and the release of neurotransmitters (neuropeptides, neurotrophins, lymphokines) from nerve endings and dermal cells, as well as increased release of histamine by skin mastocytes.

Diagnostics of the itching without rash

Because the etiology of pruritus is heterogeneous, diagnosing the underlying condition can be challenging in some cases.

More information in the material -  Diagnosis of pruritus

Medical history (including a list of medications taken) and family history are of key importance. Examination of the skin (as well as nails and hair) is also necessary; palpation of lymph nodes, liver, spleen.

Systemic studies include blood tests: complete clinical, for HIV, for sugar, for thyroid-stimulating hormones, for hematocrit and ferritin, for bilirubin, alkaline phosphase and transaminases, for urea and creatinine, for antibodies (IgE, IgG, IgM ), PCR analysis for VZV DNA. A general urinalysis and a coprogram are given. Other laboratory tests may be needed in any combination.

Instrumental diagnostics may include various x-ray studies, ultrasound of the thyroid gland, liver and gallbladder, etc.

Differential diagnosis plays an important role, considering the localization of itching, its nature and triggers, as well as the presence of other symptoms.

Treatment of the itching without rash

In each case, the  treatment of skin pruritus  should be directed to the underlying disease associated with it.

Iron deficiency anemia can be treated by taking ferrous sulfate supplements and eating more foods rich in this micronutrient (red meat, eggs, legumes, green leafy vegetables, nuts, etc.).

When detecting parasite infestation, anthelmintic drugs are used, see -  The best tablets for worms .

In therapy aimed at relieving/reducing itching, oral medications may be used. First of all, these are  Phencarol , Loratadine (other trade names are Lotharen, Claritin), Terfenadine (Trexil), Fexofenadine and other  antihistamines .

For neurogenic pruritus and pruritus associated with chronic kidney disease, anticonvulsants such as  Gabapentin  (Gabagama, Gabalept, Gabastadin) or Pregabalin may be prescribed.

In cases of paraneoplastic and psychogenic itching without rashes and itching in cholestasis, the use of antidepressants of the group of selective serotonin reuptake inhibitors -  Paxil  (Paroxetine), Sertraline (Sertraloft, Asentra), as well as tricyclic antidepressants acting on histamine H1 receptors (Doxepin or Mirtazapine) is practiced.

The drug of the group of calcineurin inhibitors Cyclosporine has an immunosuppressive effect and is used for generalized itching (contraindicated in pregnant women). The standard daily dose is 2.5 mg per kg of body weight (divided into two doses). In the list of its side effects: headache, nausea, vomiting, abdominal pain, convulsions, disorders of the kidneys, changes in the blood.

It is recommended to take vitamins of group B, as well as A, E, D.

Depending on the etiology of itching, the doctor may recommend topical agents:  ointment for itching  (including corticosteroids, which can be used for no more than two weeks in a row) or  creams for itching  - especially moisturizing and "cooling" due to the content of menthol.

Physiotherapy treatments include phototherapy (UVR), which is most effective for itchy skin in the elderly.

Alternative treatment consists of topically applying a mixture of castor oil with menthol (3:1 ratio) or turmeric powder (2:1), massaging the itchy skin with an ice cube, and lukewarm baths with ground and steamed oatmeal or Epsom salts..

You can also try herbal treatment: in the form of cool compresses with decoctions of chamomile flowers, peppermint or lemon balm herbs, anise seeds or comfrey root.

Complications and consequences

Immediate consequences and complications are secondary skin lesions due to scratching: eczematous changes (open wounds and scabs), lichenification (thickening of the skin at the sites of scratching), excoriation (scratches), hyperpigmentation (appearance of brown spots), hypopigmented atrophic scars.

These lesions can be painful, and infection is also possible.

Prevention

Dry skin can be prevented by drinking enough fluids, avoiding washing with too hot water, and using moisturizing creams. Read more -  Moisturizing creams for dry and flaky skin .

And the real prevention of most of those diseases and conditions in which pruritus appears without rashes, as doctors say, is practically impossible.

Forecast

Undoubtedly positive is the prognosis of itching without a rash with dry skin - if you take care of it properly, and itching in pregnant women, since it disappears after childbirth. And also in cases of discontinuation of the drug that causes itching without rashes.

In other cases, everything depends on the nature of the underlying disease and the success of its treatment.