Psoriasis types

Psoriasis (pronounced /səˈraɪəsɪs/) is a 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 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. Psoriasis is hypothesized to be immune-mediated and is not contagious.  Skin cells mature and are shed from the skin's surface every 28 to 30 days. When psoriasis develops, the skin cells mature in 3 to 6 days and move to the skin surface. Instead of being shed, the skin cells pile up, causing the visible lesions.

TYPES OF PSORIASIS

PLAQUE PSORIASIS

It is the most common type of psoriasis & is also called vulgaris.” “Vulgaris” means “common”. Females develop plaque psoriasis earlier than males. The first peak occurrence of plaque psoriasis is in people aged 16-22 years. The second peak is in people aged 57-60 years. Psoriatic plaques tend to be symmetrically distributed over the body. They vary in size and can appear as distinct patches or join together to cover a large area.

Features:

 Raised and thickened patches of reddish skin, called “plaques,” covered by dry, thin, silvery-white scales. When the scale is removed, the skin underneath looks smooth, red, and glossy with bleeding spots. Psoriatic plaques are well defined and have sharply demarcated boundaries. Plaques most often appear on the scalp, trunk, and limbs, with a predilection for extensor surfaces such as the elbows and knees. However, they can appear anywhere on the body, including the genitals and the soft tissue inside the mouth.

Rupioid psoriasis is characterized by scaly hyperkeratotic, grayish-brown cone-shaped lesions with concave surfaces on trunk & extremities. Areas of psoriasis which have been chronically rubbed, and that have become very thickened, are referred to as  Lichenified psoriasis.

GUTTATE PSORIASIS

 This is the second most common type of psoriasis & most frequently develop in children and young adults who have a history of streptococcal infections (about 2-3 weeks) with or without throat symptoms. Boys and girls are equally affected.

Features:

Usually beginning on the trunk and the proximal extremities the lesions may sometimes spread to involve the face, the ears and the scalp , Appears as discrete, demarcated, salmon-pink (red) teardrop like lesions, oval or circular , Usually there is a fine scale on the drop-like lesion that is much finer than the scales in plaque psoriasis.

 PUSTULAR PSORIASIS

This form of psoriasis can occur in widespread patches or in smaller areas on hands, feet or fingertips.

Features: Pus-filled blisters appearing just hours after the skin becomes red and tender. Blisters dry within a day or two but may reappear every few days or weeks. Generalized pustular psoriasis can also cause fever, chills severe itching, weight loss and fatigue.

INVERSE PSORIASIS

Not common, inverse psoriasis is also called “skin-fold,”  “flexural,” or “intertriginous” psoriasis. This type of psoriasis can be severe and incapacitating. It is more prevalent in people who are overweight and is worsened by friction and sweating.

Features:

Red and inflamed plaques that occur only in skin folds armpits, in the genital area, between the buttocks, and under the breasts. Characterized by smooth patches of red, inflamed skin. Scales do not form usually.

Genital Psoriasis - The regions of the genital area that may be affected by psoriasis include: the pubis, the genitals (the vulva, for women; the penis and scrotum, for men), the skin between the anus and vulva or anus and scrotum, and the skin around the anus. Lesion appears as  red, shiny skin around the genital area. The skin feels tight and sore. It may split or crack.

Genital psoriasis in Children (Napkin psoriasis) lesion is characterized by itching which may become infected on scratching. Scratching can also produce dryness, thickening and thus further itching of the skin.

ERYTHRODERMIC PSORIASIS

Also known as “exfoliative” psoriasis this is the least common type. This form of psoriasis can be fatal, as the extreme inflammation and exfoliation disrupt the body's ability to regulate temperature and makes it difficult for skin to perform barrier functions.

Features:

It can cover entire body with a red, peeling rash that can itch or burn intensely , It may be triggered by severe sunburn, by corticosteroids and other medications or by another type of psoriasis that's poorly controlled.

EFFECT OF PSORIASIS ON OTHER PARTS OF BODY

Mucous membranes: The tongue, anogenital area may also be involved by psoriasis in the form of whitish patches.

Oral Psoriasis : The histopathological findings in oral mucous membranes are assumed to be similar to those found in skin lesions. Epithelial parakeratosis, elongated rete ridges and the presence of an inflammatory infiltrate of te upper dermis were described in most cases . Oral candidosis was ruled out as PAS stain for fungal hyphae was negative.

Eyelids & Angle of mouth (Psoriatic blepharitis and angular stomatitis): Usually presents unilaterally, with a small plaque of psoriasis on one eyelid extending to the lid margin or on the cheek at the angle of the mouth.

Nails (Psoriatic Nails): About 50 percent of persons with active psoriasis have psoriatic changes in fingernails and/or toenails. Only less than 5% of patients present with psoriatic nails without any other cutaneous findings of psoriasis. Psoriatic changes in nails range from mild to severe.

Following nail changes can occur in psoriasis either singly or all together:

Deep pitting of nail, probably due to defects in nail growth caused by psoriasis. Yellow to yellow-pink discoloration of nail, probably due to psoriatic involvement of the nail bed. Appearance of white areas under the nail plate indicating that the nail plate is becoming detached from the nail bed  ( onycholysis). There may be reddened skin around the nail (paronychia). Crumbling of the nail plate in yellowish patches Complete loss of nail due to psoriatic involvement of the nail matrix and nail bed.

Joints (Psoriatic Arthritis): It is a lifelong condition that causes deterioration, pain, and stiffness of the joints. Psoriatic arthritis can develop within a few months of getting psoriasis or decades later, whereas some people experience only joint problems and never develop psoriasis. Almost 90% of people who develop psoriatic arthritis develop nail involvement first (pitting, ridges, or a yellowish-orange discoloration).

Slide show of psoriasis types 

SCALE OF SEVERITY

The Psoriasis Area Severity Index (PASI) is the most widely used measurement tool for psoriasis. PASI combines the assessment of the severity of the lesions and the area affected into a single score in the range 0 (no disease) to 72 (maximal disease )

Psoriasis is usually graded as:

Mild         -  affecting less than 3% of the body

Moderate - affecting 3-10% of the body

Severe     - affecting more than 10% of the body

 Also see Ref files :
 Down load files :

1-www.bakson.net

2- " Psoriasis of the tongue", Guido C. LIER, Ulrich MROWIETZ, Mona WOLFART, Patrick H. WARNKE, Jo¨rg WILTFANG1, Ingo N. G. SPRINGER, Journal of Cranio-Maxillofacial Surgery (2009) 37, 51e53 ©2008 European Association for Cranio-Maxillofacial Surgery doi:10.1016/j.jcms.2008.07.003, available online at http://www.sciencedirect.com