Plaque psoriasis : This is most common (about 80%) type of psoriasis characterized by thick patches with silver scales on dry and inflamed skin. Such skin lesions are present on scalp, knees, elbows and lower back. Skin may show cracks, bleeding, pain, irritation and burning. That’s why few doctors may prefer to call it psoriasis vulgaris.
Eczema vs Plaque Psoriasis
Scalp Psoriasis : Here one may find red, thick and dry psoriatic patches with silver scales on scalp, behind ears, forehead and neck. Sore irritating burning in scalp with cracks and bleeding is almost always present. Scalp psoriasis may also occur in infants.
Seborrheic Dermatitis vs Scalp Psoriasis
Inverse Psoriasis : Typical Presentation of this type of psoriasis is bright red shiny skin occurring in skin folds such as between buttocks, under breasts, groin area and axillae.
Trigger factors may include sweating, continuous irritation to skin i.e. excessive rubbing. Secondary fungal infection may be present here.
Note : Silver scales are absent here.
Nail Psoriasis : Up to 50% of patients with psoriasis have changes in nails like pitting (thimble symptom), yellow-brownish discoloration, subungual hemorrhages, pain-tenderness, excessive growth with powder formation. Transverse and longitudnal grooves may also be formed on nails. Nail becomes flat in the early stages of psoriatic nail disease, which later becomes concave i.e. indentation. More likely Nail psoriasis and fungal infection may co-exist together.
Note : Psoriasis of nails can develop in isolation.
Psoriatic Arthritis : It has been seen that 1-3 patients out of every 10 patients with psoriasis may develop it. Psoriatic skin lesions are either seen simultaneously or before the onset of swelling, pain, functional impairment and stiffness of joints. It may start with one joint on either side and eventually multiple joints on both sides are involved. Morning stiffness of joints or stiffness after a period of inactivity which lasts for 30-40 minutes, saucage like appearance of digits along with history of psoriasis on skin and nails confirms the diagnosis in most of the cases. X-Ray findings are typically suggestive of simultaneous presence of bone resorption and bony proliferation.
Guttate psoriasis : These are mall pink spots on arms, legs or trunk found in children or young adults. This is a milder form of Psoriasis. It is probably a an immunocomplex disease though a streptococcal proliferative factor has been seen to play an important role in proliferation of keratinocytes.
Pustular psoriasis : In this type of Psoriasis small pus formed rashes with wide spread redness is seen mostly on hands and feet. Withdrawl of corticosteroidal treatment in patients with plaque psoriasis has resulted in this type of pustular psoriasis in many patients (60%). Pustules are filled with sterile pus i.e. it is non-infectious, non-contagious. Pustules initially appear in a studded pattern on top of red plaques of skin then change their color to brown, peel and become crusted. The acute generalized form of Pustular Psoriasis is also termed Von Zumbusch and needs immediate hospitalization.
Erythrodermic psoriasis : Term Erythroderma is used for a intense bright red and inflamed skin. Withdrawl of oral corticosteroids, infections, low calcium level, intense local application and alcohal may trigger it. Difficult and bad Psoriasis some times result in this type of presentation along with dehydration, hypothermia, swelling or heart failure. Bed rest is generally advised or some serious cases may need hospitalization. Erythrodermic Psoriasis and Pustular Psoriasis generally co-exist together.