Psoriasis is one of the most common chronic skin diseases, and it affects men and women in roughly equal numbers. Approximately 70% of those who suffer with the skin condition have Type 1 or early psoriasis, a conditions which normally starts before the age of 30, usually around the age 16 for women and 21 for men. The more rare Type 2 or late psoriasis often does not first appear until after the age of 40, reaching a peak in severity around the age of 58. Psoriasis is not contagious. There are many reasons for developing the skin condition.
The three primary types of psoriasis are differentiated according to the most common symptoms: psoriasis vulgaris, pustular psoriasis and psoratic arthritis. Those who suffer with the disease can suffer from multiple types at the same time, or may be afflicted with different types at different ages.
The most frequently occurring type of this skin disease is psoriasis vulgaris, a condition which accounts for approximately 85% of all cases. The patches of red and swollen skin usually start out small and then develop to palm sized patches (plaques) which frequently affect the head, elbows and knees. Additionally the buttocks, breasts and back are often affected. The areas always appear flaky, and about half of those who suffer with psoriasis complain of itching.
The disease process as well as the appearance can vary greatly between individuals. Although a mild case of the skin condition is difficult to notice, some suffer with frequent severely affected areas. In the worst cases, up to 80% of the body can be covered with scaly skin. The finger and/or toe nails are also affected in about half of those who suffer with the condition – the nails may have a dented appearance or an odd colour, or the nails can be completely destroyed by the disease.
Psoriasis vulgaris is further divided into:
Plaque Type: The most common form of psoriasis. The plaques are at lease as large as a coin. In more severe cases, the psoriasis can cover large areas of the chest, back, arms or legs. Healing is often only partial.
Guttate Type: This variety of the skin condition is characterised by numerous small spots (smaller than a penny) which most often affect the face though sometimes also appear on the back or chest. This type is more common among young people, and often occurs in conjunction with a streptococcal throat infection.
This type of psoriasis affects less than 5% of those who suffer with the skin condition, and is more common among women. It's most often found on the soles of the feet and the palms (palmoplantar psoriasis). It's notable in that a pus is produced which is free of bacteria (sterile) – the areas can be so painful that it becomes impossible to work with the hands.
In its most severe form, the condition can be present over nearly the entire body surface (psoriasis pustulosa generalisata), but this variety is extremely rare. Almost all the skin becomes inflamed and covered in plaque, often accompanied by fever and general fatigue. This form of psoriasis can severely damage the normal function of the skin and can actually be life-threatening.
Psoriatic rheumatoid arthritis is a form of the condition which affects the joints – between five and ten percent of those who have psoriasis also suffer with this type of arthritis. It is characterised by swelling of the joints along with movement limitations. It's also common that the nails or eyes (conjunctiva or iris) are simultaneously affected.
In the distal type of psoriatic arthritis there is an asymmetrical swelling of the toe or finger joints. In about a quarter of sufferers, more commonly women, the larger joints of the collarbone (clavicle) or ankle are affected.
Equally common is the central type which primarily affects the spine and ileo-sacral joints. This type of psoriatic arthritis is more common among men.
The most severe type of psoriatic arthritis is a multiple (destructive) type; it most commonly damages the small joints in the fingers, hands, toes and feet, though sometimes also the vertebrae. The disease progresses to this type in about one in four or five of those who suffer with psoriatic arthritis. Permanent damage to the finger and toe joints is common. If the psoriasis is treated early, progression to this severe and debilitating form of the illness can often be avoided.
Causes of Psoriasis
Psoriasis is a so-called multi-factor or multiple-cause disease. The causes can be related to a genetic predisposition or to a variety of risk factors, or of course to a combination of these causes.
Approximately 30% to 40% of those who suffer with psoriasis have relatives who also have the disease. Genetic analysis reveals that the condition is more often passed on by the father. In addition to genes which code for the condition, one can also inherit a genetic resistance to the condition.
In addition to genetic factors, there is a long list of possible triggers or risk factors which can lead to an outbreak or worsening of the condition. Some possibilities are smoking and certain medications such as beta blockers, ACE inhibitors, lithium salts, antimalarial drugs, interferon, tetracycline, terbinafin and NSAIDS. There are also additional causes such as skin injuries, abrasions, surgery, sunburn, etc. Obesity, alcohol abuse and emotional stress can also cause or worsen the condition.
It's also possible that the cause of the psoriasis is an infection. Following a streptococcal infection (i.e. strep throat) or an ear infection one might experience an outbreak of psoriasis.
Additionally other infections (bacterial, viral or fungal) can lead to an outbreak of psoriasis and can also worsen an existing case. The exact mechanism involved in this relationship is not yet fully understood.
Most forms of psoriasis respond to healing clay therapy