The most common form of psoriasis, plaques may appear symmetrically on both left and right sides of the body, typically on elbows, knees, extensor surface of arms/legs, and lower back.

Fine scaling that looks like mere dandruff, or thick, crusted plaques that cover the entire scalp; begins as persistent dandruff in the scalp before spreading to the forehead, and back of neck and ears.

Red, dry and thickened skin on palms and/or soles, which may crack and cause pain; often mistaken for hand and feet eczema.

Where there are small, raindrop-like spots on the skin, often widespread on the arms, legs and torso, and could even appear on face, ears and scalp; commonly seen in children and young adults.

Affects skin folds in the groin, underarms and under the breasts with well-demarcated, red, smooth and shiny areas.

Small pus-filled blisters with surrounding redness and swelling of the skin; may be localised to the palms or soles.

Generalised red, swollen, scaly skin; though a rarer form of psoriasis, it can be life-threatening, with severe itching and pain, changes in heart rate, dehydration, heat loss, protein loss, abnormal electrolytes, and even heart failure.

Wide range and severity of nail changes, from discoloration, pitting, separation of the nail from the nail bed, to very thickened and deformed nails. Associated with higher risk of psoriatic arthritis.

Psoriasis inflammation may affect any one or multiple joints, or the soft tissue around the joints such as ligaments and tendons. They may present as pain and stiffness in joints on waking, swollen painful joints, or sausage-like swelling of fingers or toes. Often mistaken for gout, involvement of the skin provides a good clue to diagnosis. If left untreated, psoriatic arthritis is progressive and causes joint destruction and deformities. Early treatment, especially with biologics, not only limits pain but also prevents joint destruction.