What Is Psoriasis?
Unpredictable and irritating, psoriasis is one of the most baffling and persistent of skin disorders. It’s characterised by skin cells that multiply up to 10 times faster than normal. As underlying cells reach the skin’s surface and die, their sheer volume causes raised, red plaques covered with white scales. Psoriasis typically occurs on the knees, elbows, and scalp, and it can also affect the torso, palms, and soles of the feet.
The symptoms of psoriasis vary depending on the type you have. Some common symptoms for plaque psoriasis — the most common variety of the condition — include:
- Plaques of red skin, often covered with loose, silver-coloured scales; these lesions may be itchy and painful, and they sometimes crack and bleed. In severe cases, the plaques of irritated skin will grow and merge into one another, covering large areas.
- Disorders of the fingernails and toenails, including discoloration and pitting of the nails; the nails may also begin to crumble or detach from the nail bed.
- Plaques of scales or crust on the scalp
Psoriasis can also be associated with psoriatic arthritis, which leads to pain and swelling in the joints. The National Psoriasis Foundation estimates that between 10% to 30% of people with psoriasis also have psoriatic arthritis.
Dermatitis, also known as eczema, is a group of diseases that results in inflammation of the skin. These diseases are characterised by itchiness, red skin, and a rash. In cases of short duration there may be small blisters while in long-term cases the skin may become thickened. The area of skin involved can vary from small to the entire body.
Dermatitis is a group of skin conditions that includes atopic dermatitis, allergic contact dermatitis, irritant contact dermatitis, and stasis dermatitis. The exact cause of dermatitis is often unclear. Cases are believed to often involve a combination of irritation, allergy, and poor venous return. The type of dermatitis is generally determined by the person’s history and the location of the rash. For example, irritant dermatitis often occurs on the hands of people who frequently get them wet. Allergic contact dermatitis, however, can occur following brief exposures to substances a person is sensitive to.
Dermatitis was estimated to affect 245 million people globally in 2015. Atopic dermatitis is the most common type and generally starts in childhood. In the United States it affects about 10-30% of people. Contact dermatitis is twice as common in females than males. Allergic contact dermatitis affects about 7% of people at some point in time. Irritant contact dermatitis is common, especially among people who do certain jobs; exact rates are unclear.
SIGNS AND SYMPTOMS
Dermatitis symptoms vary with all different forms of the condition. They range from skin rashes to bumpy rashes or including blisters. Although every type of dermatitis has different symptoms, there are certain signs that are common for all of them, including redness of the skin, swelling, itching and skin lesions with sometimes oozing and scarring. Also, the area of the skin on which the symptoms appear tends to be different with every type of dermatitis, whether on the neck, wrist, forearm, thigh or ankle. Although the location may vary, the primary symptom of this condition is itchy skin. More rarely, it may appear on the genital area, such as the vulva or scrotum. Symptoms of this type of dermatitis may be very intense and may come and go. Irritant contact dermatitis is usually more painful than itchy.
Although the symptoms of atopic dermatitis vary from person to person, the most common symptoms are dry, itchy, red skin. Typical affected skin areas include the folds of the arms, the back of the knees, wrists, face and hands. Perioral dermatitis refers to a red bumpy rash around the mouth.
Dermatitis herpetiformis symptoms include itching, stinging and a burning sensation. Papules and vesicles are commonly present. The small red bumps experienced in this type of dermatitis are usually about 1 cm in size, red in colour and may be found symmetrically grouped or distributed on the upper or lower back, buttocks, elbows, knees, neck, shoulders, and scalp. Less frequently, the rash may appear inside the mouth or near the hairline.
The symptoms of seborrheic dermatitis, on the other hand, tend to appear gradually, from dry or greasy scaling of the scalp (dandruff) to hair loss. In severe cases, pimples may appear along the hairline, behind the ears, on the eyebrows, on the bridge of the nose, around the nose, on the chest, and on the upper back. In newborns, the condition causes a thick and yellowish scalp rash, often accompanied by a diaper rash.