Who among us hasn’t been tormented by the itch after a mosquito bite? This is due to the histamine release at the offending site. In some, it is a bit more exaggerated and an oral antihistamine or topical cream with the passage of time does the trick to provide optimal relief.
Now imagine that intensity and urge to scratch diffusely spread over your entire body in a constant and unrelenting fashion. Night and day. Where a more significant underlying cause won’t be benefitted and cured by time or a Benadryl, for instance.
That is called chronic “generalized pruritus” and its etiologies can range from the readily fixable to the necessitation of a liver transplant in those where treatment for the symptom might be refractory. In the extreme, sleep is impaired and even depression or suicidal ideation can mount.
These situations can be categorized as acute or chronic. In acute, the symptoms traditionally last less than six weeks and routinely can be cured while possibly prevented in the future should the exact trigger be identified or be of a self-limiting nature anyway. This isn’t always the case. With chronic, this temporal marker is surpassed and usually reflects a more involved inciting factor.
When the itching is of the more profound continuous variety, correcting the primary insult becomes crucial to overall health and well-being. Let’s briefly review some examples of origins of pruritus should your clinical picture not fit your persistent symptoms.
Pregnancy
There are several reasons for more than mild pruritus in pregnancy, here are two:
Late in pregnancy, (intrahepatic) cholestasis of pregnancy can precipitate the need for early delivery. Cholestasis is when the bile in the liver is sluggish or there is impedance to its proper drainage. Bile is a vital digestive material. When it prompts bile acids to accumulate due to shifting hormonal influence of the state of pregnancy, frustrating itching can result in this condition— beginning on the hands and feet mainly, then everywhere is not uncommon. There is purported to be a genetic role in addition to the hormonal one and those with it in prior pregnancies or with twin gestation or liver disease history or family history may be at higher risk. In certain circumstances, the baby needs to be delivered to protect him from serious adverse effects. Mom is usually not impacted long-term as the symptoms and resultant problems tend to dissipate within a few days of the infant’s arrival.
PUPPPS (aka Pruritic Urticarial Papules and Plaques of Pregnancy) is an itchy, bumpy rash often beginning on the pregnant abdomen (tending to spare the umbilicus and its surrounding area) then extending to the legs and beyond. Usually more frequent in multiple gestation pregnancies. Delivery of the baby is typically curative though some mom’s persist with symptoms outside the typical one week postpartum period.
Chronic Disease
Diseases of the liver and kidney can also be a culprit in chronic pruritus. Those with more severe consequences of the former experience it often with great fatigue. How it presents can be different and the causes of the liver disease to begin with have a wide spectrum from alcohol abuse history to hepatitis infections to anatomical or intrinsic or genetic liver disorders, to name a few. Basically, anything that serves as a catalyst for end-stage liver disease albeit a cancer or even a drug can be responsible. Also, those with chronic kidney failure undergoing dialysis tend to suffer from it most.
Cancer is another offender as are treatments for it as well. The locations change based on the source and severity of pruritus too. Lymphoma pruritus is regularly more intolerable than leukemic with Hodgkins being the most standard wrongdoer.
For diagnostic purposes, generalized or intense more localized pruritus is often not a solitary finding. It may predate other symptoms or alter in intensity with seasonal predilection, for example, but usually with a thorough and comprehensive history and physical examination with subsequently appropriate laboratory and testing pursuits the root perpetrator can be teased out no matter the reason. For example, when precipitated by an endocrine problem like hypothyroidism or autoimmune disorders like lupus where other findings and complaints can be easily elicited.
Infections
HIV infection or Hepatitis C are known agents. As are some parasitic and other viral infections.
Skin Disorders
Atopic Dermatitis (aka eczema) includes mild to moderate sufferers who tend to be well-controlled and managed by topical creams and whose flare-ups can be very limited. Those with more severe disease, however, endure rampant dry skin and chronic inflammation (due to their high allergic susceptibility predilection) which can require chronic oral medications for relief. So, disease severity is a compounding factor.
Psoriasis and the like would be included here, as would other autoimmune conditions like pemphigoid.
Secondary skin issues often includes an offending agent like scabies which is outside the intended scope of this article in that it is an acute cause with a simple solution. Despite that, the diffuse itching is miserable for those infected. Or, an irritant or contact dermatitis, but this would also be commonly resolved by eliminating the trigger.
Hives or Urticaria can be elicited by a food, seasonal allergy, cat, infection and even pressure of a handbag strap or exposure to the sun in the affected and susceptible individual. The final ones being called pressure urticaria or solar urticaria. Again, when recognized and addressed rapidly, they are usually only present in the relatively short-term.
In summary, the skin manifestations can be the cause and/or the effect in certain cases in particular when associated with a more overarching disease.
Anxiety and Depression can cause itching and be the consequence of those who immensely suffer.
Take Home Messages….
Itching by itself and of limited duration is routinely not of great big picture concern. And, this is the much more likely form with cures being handy and effective for the masses.
When the symptom is enduring, extreme and pervasive—physically and temporally, it is advisable to consider other causes.
Sometimes the answer is a change of detergent or ridding your environment of an allergen. In other scenarios, the symptom can be a gift to evaluating for conditions that can be improved especially when discovered before substantial progression. While in others, it can appear later in the disease course. Medications that exacerbate it can be changed, for example, as pruritus contributors exist well beyond those items and conditions listed here.
A comprehensive history and physical examination serve readily to assuage anxiety as they tell a much more complete story and, therefore, allow a doctor to explore and deduce the most relevant etiology. Determining the cause will aid in treating the symptom. This will help stop having to scratch that itch.
