Prurigo nodularis is a chronic skin disease that causes hard, itchy lumps or nodules to form on the  skin.

            And, the itching can be so intense that it causes people to scratch themselves to a point of bleeding or

pain and the scratching can cause more lesions to appear. And,these.skin nodules or lumps usually appear in

a symmetrical  pattern in easy to reach places  such as the arms,legs or upper back.

           Therefore, prurigo nodularis causes a scratch itch cycle since the more you itch,the more you scratch

and the more yopu scratch, the more you itch. Consequently,treatment includes  topical(applied on the skin),

oral and intralesional(ie,injected) corticosteroids in an allemp to alleviate the inflammation and the sense

of itching.

         In addition, antihistamines and anti-anxiety drugs  are also given orally as well as a drug notorious for

causing  birth defects called thalidomide-although this drug and its derivatives can only be given to women

of child bearing age if they are on strict birth control  measures.

         Also, there are small case studies showing the potential for  the use of methotrexate,a folic acid

antagonist widely used for autoimmune inflammatory disorders such as psoriasis.

        However,before treatment especially in recalcitrant cases,a thorough history and physical exam as well

as lab work should be done to rule out underlying medical conditions such as severe anemia or liver and

kidney disease or a type of malignancy called lymphoma as well as HIV(human immunodeficiency virus).

        In my practice,I have even done skin biopsies on various skin nodules to rule out a type of skin

cancer called squamous cell carcinoma which can eventuate from chronic itching and skin irritation.

      In conclusion,I would urge anyone with long  term itchy, crusty skin   lesions to contact their

healthcare provider  to ascertain that they are not coming from an internal disease.

,

                The basal cell carcinoma is the most common of all skin cancers,accounting for 80 percent of

non-melanoma skin cancers while the squamous cell carcinoma accounts for nearly 20 percent. 

And,non-melanoma skin cancers are more common in men with squamous cell carcinoma affecting

2 to 3 times as many men as women  while basal cell carcinoma occurs at a rate of 1 1/2 times of

men to women.

                 The American Cancer Society estimates that in 2019 an approximate 57,000 cases of

melanoma will be diagnosed in men and about 39,000 cases in women.And,the incidence of

melanoma is higher among men across most racial/ethnic populations.

                Since most cases of skin cancer link to sun exposure ,it naturally follows that the

incidence increases with age.And,the incidence of melanoma  increases after age 19 and peaks

for individuals older than 85. between 2011 and 2015 the median age for the diagnosis of melanoma

was 64.

               In addition, the incidence of specific types of skin cancer varies according to race and

ethnicity.Consequently, the risk is more than 20 times higher for the white population than for people

with darker skin such as black,American Indian/Alaskan natives,Hispanic and Asian/pacific islander populations.

And,this is due to the photoprotection provided by increased melanin in the epidermis(outer skin layer) 

of individuals with darker skin,which can filter twice as much  UV radiation as the epidermis of white 

individuals.

              As is true for the white population,basal cell carcinoma is the most common skin cancer  among

Hispanic and Asian populations . In contrast,squamous cell carcinoma is the most common skin cancer

in the black population and melanoma is the third most common skin cancer  among all racial/ethnic

populations.

             And, the highest rate of melanoma is found amiong white men and the lowest is among black

women. Although melanoma is predominate among white men compared to white women,the incidence

of melanoma in men and women is similar in black,Hispanic, and Asian/pacific islander population.

            In addition to sun exposure and radiation exposure,the risk of skin cancer is also inluenced

by co-morbid or other conditions such as non-healing ulcers and tatoos as well as arsenic in the

well water . People whose immune systems are compromised either

by cancer or the drugs used to treat it are also at increased risk for skin cancer.

            Also, skin cancer can develop in 30 to 70 % of  organ transplant patients-with a 100 fold

increase for squamous cell carcinoma ,a 24 fold increase for a very dangerous type of skin cancer

called merkel cell carcinoma(please see my previous articles on merkel cell carcinoma),a six fold

increase for basal cell carcinoma and a two fold increased risk for melanoma.

Please see my previous article entitled: Skin Cancer-not just from the sun.

           In addition, the prevalence of skin cancers is also high among individuals infected witrh

HIV (human immunodeficiency virus) and lesions in this population tend to be more aggressive.

Also,  there is a high risk of squamous cell carcinoma  associated with seropositivity  for the

human papilloma virus (HPV)  type 16 and 18 but a direct causal relationship has not been

established.

           Individuals with a history of skin cancer are at increased risk for another skin cancer and

people living in areas where the sun's rays are most intense such as the equator have an

increased risk for melanoma skin cancer.

          I saw a new patient in my office this week who came in for another problem but complied

with my request to take his shirt off when I promptly diagnosed a melanoma on his back.

         A few years ago I diagnosedf 6  patients with  melanomas in about 6 months.

        In conclusion, if you see a change in the size,shape,color or behavior of spots on your

skin,get checked by your healthcare provider.

                                 Dermatologists and other health care practitioners are often visited by a patient with a

hand rash-sometimes accompanied by a foot rash also.

                                And,specialists like dermatologists often immmediately think of eczema,psoriasis,contact

dermatitis and, perhaps,even  a fungal infection.

                              As for myself,,in addition to taking a histoery of the rash  which includes how long he or she

has been aware of it,I also list any treatments already tried and I always ask the patient what he or she thinks

may have caused it.

                             In addition,I would immediately look at the patient's fingernails and elbows,looking for signs

of psoriasis which can be manifested by a red scaley plaque like surface on the elbows and ragged fingernails.

And,often I can make the diagnosis by the simple history and physical exam described above,especially if the

feet are also involved.

                           Also, a simple test for fungus not only includes taking a skin scraping for examination under

the microscope and /or a culture to try to grow it. In addition,a fungal rash is more likely to involve 2 hands

and 1 foot or 2 feet and 1 hand-thus,adding up to 3 rather than 2 hands and/or  2 feet .

                          However, the main thrust of this narrative is to impress upon the reader that there are many

more serious causes of hand and foot rashes than the above.

                         To begin with, Woringer Kolopp disease which is a cutaneous form of an internal cancer

called lymphoma is manifested by psoriasis like thickened plaques on the hands and also the feet. It is

a type of mycoses fungoides lymphoma which can be treated by surgical excision and radiation therapy

and could easily be mistaken clinically for psoriasis.

                        Another serious disease that can appear as a rash on the hands and feet is palmoplantar

syphilis which  could be misdiagnosed as palmoplantar psoriasis. In fact, secondary syphilis has often been

called one of the great  masqueraders in dermatology since it can mimic many types of skin didease and

is often missed when it can frequently diagnosed with a simple blood test.

                       Basex syndrome is a paraneoplastic(a set of signs and symptoms that is a consequence of

cancer in the body but is not due to the local presence of cancer cells)syndrome characterized by thickened

skin on the hands or feet(ie,acral areas) as well as on the ears and nose . It is associated with malignancies

of the upper aero digestive tract such as cancer of the esophagus.

                     And, I would not want to leave this topic by not discussing the entity known as "mechanic's

hands." Mechanics hands refers to a non-itching, thickened skin eruption accompanied by scaling,fissuring and

hyperpigmentation giving one the  appearance of the calloused hands of a manual laborer.

                   In my opinion,mechanics hands could be easily misdiagnosed as hand eczema. However,

over the years mechanics hands have become recognized as a clinical marker  for pulmonary disease

as well as occurring in a condition called Dermatomyositis . People with the latter have not only skin

rashes but a 20 % incidence of internal cancer.

                  Dermatomyositis is also characterized by muscle weakness,various other skin findings as

well as a marked sensitivity to the sun.,

                 In summary, I would urge patients with  dry thickened  skin on their hands(and feet) that has

not responded to topical and (sometimes)internal steroids  or  antifungals  to see their healthcare

provder  for a detailed history and physical exam of the entire body looking for telltale signs of internal

malignancy.

                    Coming soon.

                        As a young hospital pharmacist I often dispensed nitroglycerin tablets to relieve angina

(chest pain)  caused by coronary artery disease. Later,as a physician internist I prescribed it both

while working in the emergency room and on the hospital floors.

                        Now,as a physician dermatologist, I am amazed at the many uses of this valuable

medication even when  used topically(ie,not taken internally but applied to various parts of the outside

of the body.)

                      Nitroglycerin can be applied as an ointment to the skin where it again -as in the heart-

dilates or widens small blood vessels which have been vasoconstricted by various factors including

cold temperatures,emotions,hormones and even certain medications.In addition, autoimmune

diseases  such as systemic lupus erythematosus and systemic sclerosis can also cause this

condition.

                    This vasosparm or constriction of the blood supply to body parts such as the fingers

and toes is called Raynaud's phenomenon. And,if your fingers or toes have ever been exposed to

freezing cold temperatures even for a short time,you know how discomforting it is and how fast

you have tried to rewarm them.

                    Pernio,also called chilblains,is an inflammatory response to cold on the hands and

feet and is characterized by itching,red patches and swelling and blistering.

                   Also,topical nitroglycerin ointment has been used in dermatology to  treat small

tender nodules usually found on the outer rim of the ears (ie,the helix of the ear) which are

exquisitely sensive to pressure-especially when the patient lays on them in bed at night.

This condition is called chondrodermatitis nodularis helicis (literally inflamation of the ear

cartilage)

                   In addition,topical nitroglycerin ointment is also used to relieve the severe

pain caused by long term tears in the lining of the anal cavity,called anal fissures, by

reducing the pressure on them.

                  Two of the most common side effects of topical nitroglycerin include headaches 

and dizziness,although this is even less likely with the 1 % formulation than with the

2 % product.

                  In summary, topical nitroglycerin may be a safe,inexpensive and effective

therapy wherever increased cutaneous blood flow is needed.

                    Did you know that the new onset of dry skin-called ichthyosis or "fish scale skin" in adult life

and which does not respond to lubricating creams may be related to a type of internal cancer,especially a

type of malignancy  called Hodgkins disease which is a type of lymphoma although the use of some

medications and some benign conditions such as hypothyroidism and sarcoidosis as well as malnutrition

may be the cause.

                   Acquired ichthyosis (or dry skin) has also been related to other internal cancers including

reticulolymphosarcoma,T-cell lymphoma,multiple myeloma, and lung,breast and cervical cancers.

                 In addition,this dry skin of adulthood not responding to lubricating creams can also occur in

people suffering from leprosy,AIDS,tuberculosis,and typhoid fever.

                Also, carcinomas originating in many internal body areas have a very high frequency to

metastasize(ie,spread) to the skin. In one large reported study of internal cancers there was a 5 % spread

to the skin and in 0.8 % the skin metastasis was the first sign of the internal malignancy.

               These skin metastases often present as erythematous( red) ,painless,and rapidly growing

solitary or multiple skin nodules(a small rouded lump) on the skin  or under the skin .

             Usually, the location correlates with the underlying carcinoma,ie,breast cancers most commonly

spread to the anterior(ie,front ) chest wall.

             Again,the teaching point is to get an exam by your healthcare provider for any change in

color,shape,texture or size of your skin.