Pyridoxine deficiency (also known as B6 deficiency) is a paediatric disease due to a lack of pyridoxine (or vitamin B6). The disease presents with several key symptoms including seizures, irritability, cheilitis (inflammation of the lips), conjunctivitis and neurologic symptoms. It usually becomes noticeable within the first 12 months of life in infants with a lack of pyridoxine, a coenzyme responsible for numerous essential metabolic reactions in humans. It is rarely observed, even in undeveloped countries.[1][2]

Familial pyridoxine dependency syndrome causes seizures at birth or shortly afterwards. It has been speculated that the cause of seizures in pyridoxine deficiency lies with abnormalities in the normal ratio of glutamic acid to GABA.[1] Irritiability and other neurologic symptoms, such as confusion, are common place.[2]. Anemia has also been documented as a symptom.[1]

The main cause of pyridoxine deficiency is a lack of pyridoxine in the diet. Another cause of vitamin B6 deficinecy is the use of the tuberculostatic medication isoniazid, and for this reason, it is usually replaced with vitamin B6 whilst using this drug.[2]

Decarboxylation of glutamic acid to gamma-aminobutyric acid (GABA, a neurotransmitter) and transamination of glutamic acid to alpha-ketoglutaric acid are both impaired in animals when suffering from pyridoxine deficiency.[1] Neurologic symptoms are most likely due to diminished affinity of pyridoxine for the apoenzyme, which can only be overcome by increasing tissue concentrations of the enzyme.[1]

Pyridoxine deficiency is a very rare condition, even in undeveloped countries. A handful of cases were seen in between 1952 and 1953, particularly in the United States, and occurered in a small percentage of infants who were fed a formula lacking in pyridoxine.[1] A positive diagnosis test for pyridoxine deficiency can be assertained by measuring erythrocyte levels of aspartate aminotransferase and transketolase in serum.[2]

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Pyomyositis, also known as tropical pyomyositis or myositis tropicans is a bacterial infection of the skeletal muscles which results in a pus-filled abscess. Pyomyositis is more common in tropical areas but can also occur in the temperate zones.

Pyomyositis is most often caused by the bacterium Staphylococcus aureus.[1] The infection can affect any skeletal muscle, but most often infects the large muscle groups such as the quadriceps or gluteal muscles.

In tropical regions, the infection often follows minor trauma, while in temperate zones the infection typically occurs in people with immune deficiencies.

The abscess within the muscle must be drained surgically and antibiotics given to fully clear the infection.

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Pyoderma gangrenosum is a disease that causes tissue to become necrotic, causing deep ulcers that usually occur on the legs. When they occur, they can lead to chronic wounds. Ulcers usually initially look like small bug bites or papules, and they progress to larger ulcers. Though the wounds rarely lead to death, they can cause pain and scarring.

The disease was identified in 1930. It affects approximately 1 person in 100,000 in the population. Though it can affect people of any age, it mostly affects people in their 40s and 50s.[1]

There are two main types of pyoderma gangrenosum:[1]

Other variations are[2]:

Though the etiology is not well understood, the disease is thought to be due to immune system dysfunction, and particularly improper functioning of neutrophils. At least half of all pyoderma gangrenosum patients also suffer from illnesses that affect their systemic function.[1] For instance, ulcerative colitis, Crohn’s disease, rheumatoid arthritis, myeloma sufferers have the condition. It can also be part of a syndrome, for instance in PAPA syndrome.

The common conditions associated with pyoderma gangrenosum are:

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Purpura (from the Latin, purpura, meaning “purple”) is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin. Purpura measure 0.3-1 cm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm[1].

This is common with typhus and can be present with meningitis caused by meningococcal meningitis or septicaemia.

Purpura is a common and unspecific medical sign, however the underlying mechanism commonly involves one of the following:

There are also cases of psychogenic purpura described in the medical literature,[2] some claimed to be due to “autoerythrocyte sensitization.” Other studies[3] suggest, that local (cutaneous) activity of tPA can be increased in psychogenic purpura, leading to substantial amounts of localized plasmin activity, rapid degradation of fibrin clots, and resultant bleeding. Petechial rash is also characteristic of a rickettsial infection.

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Pulmonary valve stenosis is a valvular heart disease in which outflow of blood from the right ventricle of the heart is obstructed at the level of the pulmonic valve. This results in the reduction of flow of blood to the lungs. Valvular pulmonic stenosis accounts for 80% of right ventricular outflow tract obstruction.[1] While the most common cause of pulmonary valve stenosis is congenital heart disease, it may also be due to rheumatic heart disease or a malignant carcinoid tumor.[1]

Symptoms include jugular venous distention, cyanosis (usually visible in the nailbeds), right ventricular hypertrophy and general symptoms of lowered oxygenation of the blood. When the stenosis is mild, it can go unnoticed for many years. If stenosis is severe, you may see sudden fainting or dizziness if exercised too much, you may also experience an enlarged liver (hepatomegaly) and swelling in the legs (edema).

The initial evaluation of pulmonary valve stenosis involves echocardiography. The degree of stenosis is typically determined by the peak pressure gradient across the valve.[1] If the peak gradient across the valve is greater than 50 mmHg, intervention is generally warranted. If the peak gradient is < 25 mmHg, no intervention is generally needed. If the gradient is between 25 and 50 mmHg, it is a gray area.

Valve replacement or surgical repair (depending upon whether the stenosis is in the valve or vessel) may be indicated. If the valve stenosis is of congenital origin, balloon valvuloplasty is another option. Depends on case.

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A pulmonary sequestration, also known as a bronchopulmonary sequestration or a cystic lung lesion, is a medical condition where a piece of tissue that develops into lung tissue is not attached to the pulmonary blood supply and does not communicate with the other lung tissue. Often it gets its blood supply from the thoracic aorta. Communication is a medical phrase indicating that it is not connected to the standard bronchial airways and that it performs no function in respiration.

This condition is normally detected in children and is generally held to be congenital in nature. The treatment for this is a segmentectomy via a thoracotomy. More and more, these lesions are diagnosed by prenatal ultrasound.

There are two different kinds of pulmonary sequestrations, intralobar and extralobar. The generally accepted difference between these seems to whether or not the sequestration has its own pleura, although some thoracic surgeons seem to prefer a definition that relates to the degree of vascular connection for the sequestration.

Symptoms can vary greatly, but they include a persistent dry cough.

Sequestrations can be identified in-utero via an abnormal artery on ultrasound. The gold standard for diagnosis is pulmonary angiography. But since it is a very invasive procedure, it is getting replaced by CT Scan with a contrasting fluid, as the investigation of choice. Further studies are required for comparing sensitivity and specificity of angiograms versus ct scans in diagnosing pulmonary sequestration.

Failure to have a pulmonary sequestration removed can lead to a number of complications. These include:

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In medicine, pulmonary hypertension (PH) is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion. Pulmonary hypertension can be a severe disease with a markedly decreased exercise tolerance and heart failure. It was first identified by Dr. Ernst von Romberg in 1891.[1] According to the most recent classification, it can be one of five different types: arterial, venous, hypoxic, thromboembolic or miscellaneous.[2]

Because symptoms may develop very gradually, patients may delay seeing a physician for years. Common symptoms are shortness of breath, fatigue, non-productive cough, angina pectoris, fainting or syncope, peripheral edema (swelling of the limbs which commonly manifests around the ankles and feet), and rarely hemoptysis (coughing up blood). Pulmonary arterial hypertension (PAH) typically does not present with orthopnea or paroxysmal nocturnal dyspnea, while pulmonary venous hypertension typically does.

In order to establish the cause, the physician will conduct a thorough medical history followed by a physical examination. A detailed family history is established to determine whether the disease might be hereditary|familial. A history of exposure to drugs such as cocaine, methamphetamine, alcohol leading to cirrhosis, and smoking leading to emphysema are considered significant. A physical examination is performed to look for typical signs of pulmonary hypertension, including a loud P2 (pulmonic valve closure sound), (para)sternal heave, jugular venous distension, pedal edema, ascites, hepatojugular reflux, clubbing etc. Evidence of tricuspid insufficiency is also sought and, if present, is consistent with the presence of pulmonary hypertension.

Because pulmonary hypertension can be of five major types, a series of tests must be performed to distinguish pulmonary arterial hypertension from venous, hypoxic, thomboembolic, or miscellaneous varieties.

A physical examination is performed to look for typical signs of pulmonary hypertension. These include altered heart sounds, such as a widely split S2 or second heart sound, a loud P2 or pulmonic valve closure sound (part of the second heart sound), (para)sternal heave, possible S3 or third heart sound, and pulmonary regurgitation. Other signs include an elevated jugular venous pressure, peripheral edema (swelling of the ankles and feet), ascites (abdominal swelling due to the accumulation of fluid), hepatojugular reflux, and clubbing.

Further procedures are required to confirm the presence of pulmonary hypertension and exclude other possible diagnoses. These generally include pulmonary function tests, blood tests to exclude HIV, autoimmune diseases, and liver disease, electrocardiography (ECG), arterial blood gas measurements, X-rays of the chest (followed by high-resolution CT scanning if interstitial lung disease is suspected), and ventilation-perfusion or V/Q scanning to exclude chronic thromboembolic pulmonary hypertension. Biopsy of the lung is usually not indicated unless the pulmonary hypertension is thought to be due to an underlying interstitial lung disease. But lung biopsies are fraught with risks of bleeding due to the high intrapulmonary blood pressure. Clinical improvement is often measured by a “six-minute walk test”, i.e. the distance a patient can walk in six minutes. Stability and improvement in this measurement correlate with better survival. Blood BNP level is also being used now to follow progress of patients with pulmonary hypertension.

Diagnosis of PAH requires the presence of pulmonary hypertension with two other conditions. Pulmonary artery occlusion pressure (PAOP or PCWP) must be less than 15 mm Hg (2000 Pa) and pulmonary vascular resistance (PVR) must be greater than 3 Wood units (240 dyn•s•cm-5 or 2.4 mN•s•cm-5).

Although pulmonary arterial pressure can be estimated on the basis of echocardiography, pressure measurements with a Swan-Ganz catheter provides the most definite assessment. PAOP and PVR cannot be measured directly with echocardiography. Therefore diagnosis of PAH requires right-sided cardiac catheterization. A Swan-Ganz catheter can also measure the cardiac output, which is far more important in measuring disease severity than the pulmonary arterial pressure.

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Psoriasis (pronounced /s?’ra??s?s/) is a chronic, non-contagious autoimmune disease which affects the skin and joints. It commonly causes red scaly patches to appear on the skin. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of inflammation and excessive skin production. Skin rapidly accumulates at these sites and takes on a silvery-white appearance. Plaques frequently occur on the skin of the elbows and knees, but can affect any area including the scalp and genitals. In contrast to eczema, psoriasis is more likely to be found on the extensor aspect of the joint.

The disorder is a chronic recurring condition which varies in severity from minor localised patches to complete body coverage. Fingernails and toenails are frequently affected (psoriatic nail dystrophy) – and can be seen as an isolated finding. Psoriasis can also cause inflammation of the joints, which is known as psoriatic arthritis. Ten to fifteen percent of people with psoriasis have psoriatic arthritis.

The cause of psoriasis is not known, but it is believed to have a genetic component. Factors that may aggravate psoriasis include stress, excessive alcohol consumption, and smoking.[1] There are many treatments available, but because of its chronic recurrent nature psoriasis is a challenge to treat.

Psoriasis is probably one of the longest known illnesses of humans and simultaneously one of the most misunderstood. Some scholars believe psoriasis to have been included among the skin conditions called tzaraat in the Bible.[2] In more recent times psoriasis was frequently described as a variety of leprosy. The Greeks used the term lepra (?ep?a) for scaly skin conditions. They used the term psora to describe itchy skin conditions. It became known as Willan’s lepra in the late 18th century when English dermatologists Robert Willan and Thomas Bateman differentiated it from other skin diseases. They assigned names to the condition based on the appearance of lesions. Willan identified two categories: leprosa graecorum and psora leprosa.

While it may have been visually, and later semantically, confused with leprosy it was not until 1841 that the condition was finally given the name psoriasis by the Viennese dermatologist Ferdinand von Hebra. The name is derived from the Greek word psora which means to itch.[3]

In Ayurveda, the herbal system of India, a condition which clinically resembles psoriasis was described in sources that historians believe date from the first or second centuries AD.[citation needed]

It was during the 20th century that psoriasis was further differentiated into specific types.

The symptoms of psoriasis can manifest in a variety of forms. Variants include plaque, pustular, guttate and flexural psoriasis. This section describes each type (with ICD-10 code [6]).[4]

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In medicine (pulmonology), psittacosis — also known as parrot disease, parrot fever, and ornithosis — is a zoonotic infectious disease caused by a bacterium called Chlamydophila psittaci (formerly Chlamydia psittaci) and contracted not only from parrots, such as macaws, cockatiels and budgerigars, but also from pigeons, sparrows, ducks, hens, gulls and many other species of bird. The incidence of infection in canaries and finches is believed to be lower than in psittacine birds.

The word “ornithosis” is only a synonym for “psittacosis” in certain contexts [1]: more generally the term is applied to any infection that is spread by birds.

In birds, Chlamydophila psittaci infection is referred to as avian chlamydiosis (AC). Infected birds shed the bacteria through feces and nasal discharges, which can remain infectious for several months. Many strains remain quiescent in birds until activated under stress. Birds are excellent, highly mobile vectors for the distribution of chlamydial infection because they feed on, and have access to, the detritus of infected animals of all sorts.

C. psittaci in birds is often systemic and infections can be inapparent, severe, acute or chronic with intermittent shedding. Symptoms in birds include “inflamed eyes, difficulty in breathing, watery droppings and green urates.”[2]

Initial diagnosis may be via symptoms, but is usually confirmed via an antigen and antibody test. A PCR-based test is also available. Although any of these tests can confirm psittacosis, false negatives are possible and so a combination of clinical and lab tests is recommended before giving the bird a clean bill of health.[2]

Infection is usually via the droppings of another infected bird, though it can also be transmitted via feathers and eggs,[3] and are typically either inhaled or ingested.[2]

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Proteus syndrome is a congenital disorder that causes skin overgrowth and atypical bone development, often accompanied by tumors over half the body. Proteus syndrome is named after the Greek sea-god Proteus, who could change his shape.

Since Dr. Michael Cohen identified it in 1979,[1] only a few more than 200 cases have been confirmed worldwide, with estimates that about 120 people are currently alive with the condition.[2] As attenuated forms of the disease may exist, there could be many people with Proteus Syndrome who remain undiagnosed. Those with obvious manifestations who are most readily diagnosed are also, unfortunately, the most severely disfigured.

This extremely rare condition would have remained obscure, were it not for the fact that Joseph Merrick — immortalized as the “Elephant Man” for a look imparted by his large facial tumours and the grayish hue of his overgrown skin — was lately diagnosed as having a particularly severe case of Proteus syndrome rather than, or in addition to, the neurofibromatosis that doctors once thought he had.[3] Oddly, Merrick’s left arm and his genitals were entirely unaffected by the condition that grotesquely deformed every other portion of his body.

Proteus syndrome causes an overgrowth of skin, bones, muscles, fatty tissues, and blood and lymphatic vessels.

Proteus syndrome is a progressive condition, wherein children are usually born without any obvious deformities. As they age, tumours as well as skin and bone growths appear. The severity and locations of these various asymmetrical growths vary greatly but typically the skull, one or more limbs and soles of the feet will be affected. There is a risk of premature death in affected individuals due to deep vein thrombosis and pulmonary embolism caused by the vessel malformations that are associated with this disorder. Further risks may occur due to the mass of extra tissue – Merrick himself died when the weight of his head dislocated his neck while asleep.

The disorder itself does not directly cause learning impairments: the distribution of intelligence among sufferers of Proteus syndrome mirrors that of the general population. However, the growths may cause secondary damage to the nervous system leading to cognitive disability. In addition, the presence of visible deformity may have a negative effect on the social experiences of the sufferer, causing cognitive and social deficits.

Afflicted individuals are at increased risk for developing certain tumors including unilateral ovarian cystadenomas, testicular tumors, meningiomas and monomorphic adenomas of the parotid gland.

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