Wednesday 26 March 2014

Dermatology Made Simple : Classification of Urticaria:

 Classification of Urticaria:

Classification on basis of duration of symptoms:

Acute Urticaria:

Symptoms last for less than 6 weeks.

Chronic Urticaria:

Symptoms last for more than 6 weeks.

Classification based on underlying cause:

Idiopathic:

In 50 % of cases,urticarial is idiopathic or has no underlying cause.

This is most common form of urticarial.

Intermittent fleeting wheels occur at any skin site with or without angioedema.

Lesions maybe annular,popular or even serpiginous.

The lesions may last from minutes to hours and may recur over less than 6 weeks.

Trigger factors for urticarial include:

Infections

Food

Medications

Contact allergic

Cholinergic Urticaria:

This occurs after a warm shoer/bath or after exercise.

Patients are usually 10 – 30 years old.

Lesions consist of pinhead sized wheals with a red flare around them

Solar Urticaria:

This occurs rarely in clinical practice.

In this condition,sunlight causes  an acute urticarial eruption.

Symptoms occur within 30 minutes of sunlight exposure.

Lesions resolve quickly on cessation of sunlight exposure.

Differential Diagnosis of Solar urticaria are:

Porphyria : Lesions resolve with scarring

Polymorphic light eruption: Lesions take days to weeks to resolve.

Pressure Urticaria:

These lesions occur at site of pressure on the skin.

It usually presents in pressure areas.

The rash appears after 6 hours of contact.

Symptoms are usually recurrent.

It usually responds to Dapsone or Montelukast.




Urticarial Rash



Urticarial Hives

Tuesday 25 March 2014

Computer Studies Made Simple : Plotters

Plotters

A plotter is an output device that produces high quality image graphics using different colors.

Applications

Plotters are used for:

Charts

Graphs

Maps

Architectural designs.

It has got markers in a  mechanical arm and draws lines on paper.

Types of plotters:

1.Flat bed plotter:

This is used to plot or draw images.

It contains pens for drawing images.

The paper is placed on table like surface.

Software gives instructions to the pen to move down on the paper and pen moves in a way to create the 
required images.

They usually contain one or more pens of different colors and widths.


2.Drum plotter:

This works by using a rotating cylinder.

The drawing pens are attached to the cylinder.

The pens move from one side to another and create the required images.






Sunday 23 March 2014

Dermatology Made Simple : Management Of Urticaria:




Management Of Urticaria

1.Avoidance of allergens/trigger factors.

2.Treatment of Underlying  Medical condition.

3.Pharmacological Treatment:

Antihistamine:

H1 receptor blockers : Cetrizine,loratidine and chlorpheniramine

Combination of H1 receptor blockers and H2 receptor blockers in severe cases.

Leukotriene receptor antagonists:

Montelukast and Zafirlukast

Oral Corticosteroids maybe used in very severe eruptions.

Intramuscular adrenaline in life threatening scenarios and anaphylactic shock.

Clinical History in Urticaria:

This is of primary significance.

It is important to ask about onset,duration and course of lesions and associated rash and swelling.

Urticaria is very itchy and  angioedema is painful.

Patients with urticarial complain of itcy spots and rashes lasting minutes or hours. Usually less than 24 hours 
and that resolve leaving no scars or marks.

In angio-edema,there may be swelling of face and lips and tongue that may last for hours and days.

Incase the lesions last for more than 24 hours and is painful and resolves with bruising,urticarial vasculitis is more likely than ordinary urticaria.

Pateints may occasionally feel unwell before the onset of rash or swelling and in severe reactions,anaphylaxis may result.

It is important to find out about any possible trigger before onset of rash,eg any food eaten,medications taken,insect stings,infections etc.



Saturday 22 March 2014

Computer Studies Made Simple : Non-impact printers



Non-impact printers

A non-impact printer prints characters and graphics on a piece of paper without striking the paper.

Some of these papers use spray ink while others use heat and pressure to create images.

These printers are faster than impact printer.

Types of non-impact printers:

A.Laser printer

B.Inkjet Printer

C.Thermal printer

A.Laser printer:

These are non-impact printers.

They work in a way similar to photocopying machine.

The laser creates images on a paper by laser beam.

LASER means Light amplification by stimulated emission of Radiation.

Laser throws magnetic material powder on paper in the form of microscopic dots.

The density of these dots ranges from 300 to 2000 dots per inch.

The printing speed of laser printers is from 5 to 300 pages per minute.

Laser printers are also called as page printers.

They print one page at a time.

They are faster than inkjet and dot matrix printers.

Color printing with laser pinters is very costly.

B.Inkjet Printer:

An ink jet printer is a type of non-impact printer.

It prints characters and graphics by spraying tiny drops of liquid ink on paper.

These printers can produce quality text and graphics in both black and white color.

Inkjet printers are slower than laser printers.

They print 1 – 6 pages / minute.

Its print quality is higher than dot matrix printer.

They are also relatively inexpensive.

Most inkjet printers usually have two print cartridges : one containing black and other containing color.

Another type of inkjet printer is called bubble jet printer.

Thermal printer:

This uses color waxes and heat to produce images by burning dots on special paper.

The color wax sheets arenot required for black  and white output.

Thermal printers are expensive and require costly paper.


These printers are used to create the highest quality color printing. 

Monday 17 March 2014

Dermatology Made Simple : Urticaria

Urticaria

Urticaria is defined as transient pruritic swellings on the skin.

It is also termed as wheals or hives.

Pathophysiology:

It occurs due to oedema in the superficial layers of the skin.

Causes:

It can occur in association with:

Allergic reactions

Infection or

Physical stimuli

In association with vasculitis,pemphigoid or dermatitis herpetiformis.

Angio-oedema is painful rather than itchy.

It appears as diffuse swelling that affects the deeper layers of the skin.

It can occur rapidly and may involve the mucous membranes.

Urticaria is a fairly common skin disorder that may occur as a single episode or recurrent.

The prognosis is varied and depends upon the underlying cause.

Pathophysiology:

Urticaria results from release of histamine,bradykinin and pro-inflammatory mediators being released from 
basophils and mast cells in response to various trigger factors.

These chemicals released by degranulation cause capillaries and venules to leak causing tissue oedema.

Urticaria maybe IgE mediated with cross linking of two adjacent IgE receptors or complement mediated causing direct degranulation of mast cells or mast cells may directly be stimulated by an exogenous or 
unknown substance.

In patient with chronic urticarial, histamine canbe released spontaneously or in response to non-specific 
stimuli and their vasculature is more sensitive to histamines.

.

Sunday 16 March 2014

Computer Studies Made Simple : Printers

Printers

A printer is an output device that prints characters,symbols and graphics on paper.

The printed output is called Hard Copy.

Print resolution is usually measured in Dots per inch DPI.

Types of Printers:

1.Impact Printers:

This works like a type writer.

It prints characters or images by striking print hammer or wheel against an inked ribbon.

Dot matrix and line printers are examples of impact printers.

2.Non-impact Printers:

These print character and graphics on a piece of paper without striking the paper.

Some of these printers use spray ink while others use heat and pressure to create images.

These printers are faster than impact printer.

Inkjet and laser printers are examples of non-impact printers



Thursday 13 March 2014

Dermatology Made Simple : Pruritis

Dermatology Made Simple : Pruritis

Pruritis:

Pruritis is defined as itching of the skin

Pruritis maybe generalized or localized and maybe associated with normal skin or skin changes.

Causes of Localized Pruritis with Skin Changes:

These include:

Eczema

Psoriasis

Lichen Planus

Dermatitis Herpetiformis

Insect bites

Contact Dermatitis

Urticaria

Angioedema

Causes of Generalized Pruritis with skin Changes:

This is seen in widespread inflammatory skin changes such as:

Widespread eczema

Psoriasis

Scabies

Graft Vs Host Disease

Allergic drug eruption

Pruiritis with Normal Skin:

There are different causes for this:

Infections:

Filariasis,HIV and Hookworm

Malignancy:

Lymphoma,Leukemia,Myeloma

Haematological:

Polycythemia,Iron Deficiency Anemia

Endocrinological Causes:

Diabetes,Myxoedema,Hyperthyroidism

Drugs:Opioids

Chronic Renal Failure

Hodgkin”s Disease

Investigations:

Full Blood Count

CRP

U and Es

ESR

Chest X Ray

Thyroid Function Tests

Serum Glucose

Urine Routine Exam

Skin biopsy

Management :

Treat and Identify the underlying cause.

Aim to suppress the sensation of itch by Medication or Behavioural Therapy.

Apply Cold emollients over the skin lesions.

Topical Local anesthetics are also effective.

Topical and systemic antihistamines canbe fairly effective.

Most commonly Used H1 receptor Antihistamines include:

Cetrizine,Levocetrizine,desloratidine and fexofenadine.









Tuesday 11 March 2014

Computer Studies Made Simple: Display Screens


Computer Studies Made Simple: Display Screens

Flat Display Pannel:

These are light weight display screens that take less space.

They utilize much less power than Cathode Ray Tube Monitors.

Flat Panel Display are made up of two plates of glass with a substance medium in between them.

Flat Display Screens have three types of technologies:

A.Gas Plasma Display:

This display uses a gas that emits light in presence of an electric current.

B.Liquid Crystal Display :

This display screen contains a substance called Liquid Crystal.

The molecules of this substance line up in such a way that the light behind the screen can create an image by either getting blocked or unblocked.

C.Electro lumiscent Display:

This type of display screen contains a susbstance that glows when getting charged by an electric current.

Advantages of Flat Panel Display over CRT :

Flat Panel Display :

Do not emit Harmful radiation.

Weight is less than CRT.

Utilize Crystal Technology

Require less space.

Use less energy that CRT monitor.

Is utilized in computer notebooks,PDAs and PCS.



Thursday 6 March 2014

Dermatology Made Simple : General principles for Management of Eczema Part 2

In case of infected eczema,antibiotics either systemic or topical should be used.

Topical Antibiotics

Topical antibiotics include: fusidic acid,silver sulfadiazine,polymyxins,neomycin and mupirocin.

Topical antibiotics should be used for at least a maximum period of 2 weeks continuously to reduce the risk 
of developing resistance in bacteria.

Systemic antibiotics include : Flucolxacillin (amoxicillin,penicillin)

Erythromycin ,clarithromycin,azithromycin

Ciprofloxacin,levofloxacin and ofloxacin.

Antibacterial emollient washes can be useful in active cutaneous infections as well as prophylactically.

Phototherapy

This is usually done with Narrow band UVB (TL-01) or PUVA (psoralen with UVA)

This is highly effective for generalized eczema.

Each course lasts for 6 – 8 weeks and patients have to attend atleast 2 to 3 times per week.

However there is a limit to the number of courses (cumulative dose) of phototherapy that any individual 
patient can receive before an increased risk of skin cancer occurs.

Systemic Immunosuppressants:

These are used in severely wide spread disease not controlled with topical therapy.

Dermatology specialists prescribe a reducing course of oral prednisolone 30 mg for 5 days,then reducing by 5 mg every 5 days to control very sever generalized acute eczema in adults.

Long term oral steroids shouldnot be used to control eczema .

Rather azathioprine,ciclosporin,mycophenolate mofetil and methotrexate canbe used for long term management.

If possible,levels of TPMT : Thiopurine methyl transferase should be checked before starting azathiopurine.


Wednesday 5 March 2014

Computer Studies Made Simple: Pointing Devices:



Pointing Stick:

This is a pressure sensitive device.

It exists between the keys on a keyboard.

The pointer on the screen moves when the user pushes the pointing stick.

It requires no additional space or cleaning likemouse.


Pointing stick is normally used with notebook computers.

Graphics Tablet:

This consists of a flat pad (the tablet) connected by a wire to a stylus or a puck.

A stylus is a pen like device used to create sketches and images.

A puck is a copying device used to copy an image.

A puck looks like a mouse.

When a puck moves,the tablet converts these movements into digital signals that are input to the computer.

A designer can produce  very accurate drawings using graphics tablets.

Graphic tablets are often used to make maps and engineering drawings.

The puck is specially used to trace a drawing and store it in the computer in digital form.

Light Pen:

This is a hand held like device.

It has light sensitive stylus.

It is connected by a ire to the computer.

It has a device at its tipo that emits light.

The pen sends information to the computer when user touches tip of the pen on certain areas of a specifically designed screen.


Light pen is usually used by engineers,graphic designers and illustrators.

Tuesday 4 March 2014

Dermatology Made Simple : General Management of Eczema


General Management of Eczema

Main Points/Genral Principls:

1.Treat the patient as a whole and not just the disease.

2.Quantify the psychological impact of the disease and provide support.

3.Identify the type of treatment most suitable for a patient.Some patients may find a cream or topical preparation unsuitable and would desire for tablets or systemic therapy,Others may have the opposite priority.

4.Identify the magnitude / severity of the disease.

Milder forms of disease would respond to topical preparations while the more severe ones only respond to systemic therapy.

In others such as exogenous eczema,mere removal of an allergen can cure the symptoms.

Dry Skin :

For dry skin,the following treatments maybe effective:

Emollients

Moisturizers

Active eczema:

The best treatment for active eczema is topical steroids.

For mild eczema,very low potency steroids are effective such as Hydrocortisone.

For moderate to sever eczema,potent topical steroids are effective such as: 

Mometasone,betamethasone,fluocinolone acetonide)

Other modalities:

Immunomodulators eg Tacrolimus and Pimecrolimus.


Occlusion of topical therapies with bandages.Infection should be excluded before this is being carried out. 

Monday 3 March 2014

Computer Studies Made Simple: Display Screens : CRT Monitor

CRT Monitor

CRT monitors is the most common form of display screen.

It looks like a television.

It can display text and graphics.

It uses a CRT : Cathode Ray Tube.

CRT tube creates an image on the screen by an electronic beam.CRT consists of one or more guns that fire 
a beam of electrons inside the screen.

The screen is coated with very tiny phosphate dots from the inside.

The beam of electrons repeatedly falls on the surface of the screen.

Every beam fall only takes a fraction of a second.

CRT in monitors consist of three guns.

The guns generate Red Green and Blue colors (RGB).


The other colors are generated with combination of these three colors. 

Sunday 2 March 2014

Dermatology Made Simple : Investigations for Contact Dermatitis


Investigations for Contact Dermatitis

1.Detailed History is mandatory

2.Details of Occupation

3.Any improvemets when away from work.

4.Patch Testing :

These tets are used to determine the type of allergen causing the contact dermatitis.

The test patches are left on the patient”s upper back for 48 hours and the removed and any positive 
reactions are noted.

Another examination is carried out at 96 hours to note any late reactions.


While these tests are being carried out,the patients should not be taking any systemic immunosuppressants.