Psoriasis: Why the Skin Flares and How It's Treated

Few conditions are as visible — or as misunderstood — as psoriasis. The raised, scaly patches can draw stares and unkind assumptions, and many people who have it spend years being told it's down to hygiene or stress. It is neither of those things, and it is not contagious. Psoriasis is an immune-driven condition, and understanding what is actually happening in the skin is the first step to treating it well. This guide explains what psoriasis is, why it flares, how it's managed today, and — honestly — where regenerative medicine does and doesn't fit. For the bigger picture of immune-driven disease, see our guide to what an autoimmune disease is.

What is psoriasis?

Psoriasis is a chronic, immune-mediated skin disease. In a healthy immune system, inflammation is a short-lived, targeted response; in psoriasis, immune cells in the skin stay switched on and drive skin cells to multiply far faster than normal ²³. Because new skin cells are produced quicker than old ones can shed, they accumulate at the surface as thick, scaly patches called plaques.

These plaques most often appear on the elbows, knees, scalp, lower back, and hands and feet, and the skin around them can look red, pink, or darker depending on skin tone, often topped with silvery scale ¹. There are several forms of the condition, but plaque psoriasis is by far the most common, affecting roughly 85–90% of people with psoriasis ³. It can also affect the nails — causing pitting, thickening, or discolouration — and, in some people, the joints.

What's happening in the skin?

The engine of psoriasis is the immune system, not the skin itself. Activated immune cells (T lymphocytes) release signals that tell skin cells, called keratinocytes, to proliferate ³. Skin that would normally take around a month to renew and shed instead turns over in a matter of days — so cells stack up at the surface before the older layers can fall away. That pile-up is the plaque.

This is also why two stubborn myths are simply wrong. Psoriasis is not contagious — you cannot catch it or pass it on by touch — and it is not caused by being unclean ¹. It is a difference in how the immune system behaves, with a strong genetic component.

A flaring condition — and its triggers

Like many immune-driven conditions, psoriasis tends to come and go in flares rather than staying constant. Certain things are known to set off or worsen flares: injury to the skin such as a cut, scratch, or sunburn (the so-called Koebner phenomenon), streptococcal throat infections, psychological stress, smoking, heavy alcohol use, and some medications ³. Many people also find their skin is worse in winter and eases in summer.

Knowing your own triggers is part of management — not because avoiding them replaces treatment, but because it can make flares less frequent and less severe.

Who gets psoriasis?

Psoriasis is common, affecting roughly 2% of adults in many populations (estimates worldwide range from under 1% to nearly 5%) ³. It can begin at any age but tends to start in two waves — most often between about 15 and 20, and again around 55 to 60 ³. Genetics matter: having a close relative with psoriasis raises your likelihood of developing it, though it is the combination of genetic susceptibility and environmental triggers that determines whether and when it appears ².

More than skin deep

Psoriasis is often described as "just" a skin condition, but it is increasingly understood as a systemic inflammatory disease. The clearest example is psoriatic arthritis — a form of inflammatory joint disease that develops in around 30% of people with psoriasis, causing joint pain, stiffness, and swelling that, untreated, can damage the joints ³. Skin symptoms usually come first, which is why any new joint pain is worth raising with your doctor.

Psoriasis is also associated with a higher likelihood of cardiovascular disease, metabolic syndrome, and mood conditions such as depression ³. None of this is cause for alarm, but it is the reason good care looks beyond the skin — and treats the inflammation, not only the scale.

How is psoriasis treated?

There is no cure for psoriasis, but treatment has advanced dramatically, and most people can achieve clear or near-clear skin with the right plan. Care is tiered to the severity and how much skin is involved ³¹:

• Topical treatments — the first step for mild-to-moderate disease: emollients (moisturisers), topical corticosteroids, and vitamin-D-based creams applied directly to plaques to calm inflammation and slow cell growth.
• Phototherapy — controlled, medically supervised ultraviolet light (narrow-band UVB) that slows the over-active skin-cell production, used when topicals aren't enough.
• Systemic medications — for moderate-to-severe disease, drugs that work throughout the body, such as methotrexate, to dial down immune activity.
• Biologic therapies — the modern leap forward. These targeted injectable drugs block the specific immune signals (such as TNF, IL-17, and IL-23 pathways) that drive psoriasis, and they can clear the skin for many people who didn't respond to older treatments ³.

Because the more powerful treatments act on the immune system, they're prescribed and monitored by a dermatologist, with the plan adjusted over time.

Where does regenerative medicine fit?

Here, honesty matters more than enthusiasm. For psoriasis, the genuine breakthrough of the last two decades has been biologic medicine, not cell therapy — and the right first stop for psoriasis is dermatology, not a regenerative clinic. Mesenchymal stem cells are being studied for immune-mediated conditions because of their signalling effects on inflammation, and psoriasis appears in that early research, but it remains investigational — there is no established, approved stem-cell treatment for psoriasis, and it is not a substitute for proven dermatologic care.

We think it's important to say that plainly. (If you're curious about what these cells are actually thought to do — mostly signalling, not rebuilding — our honest explainer on what stem cells can really do lays it out.) The short version: for psoriasis, see a dermatologist first, be wary of anyone selling cell therapy as a cure, and treat the well-evidenced options as the foundation.

What we see at the clinic

When people ask us about regenerative options for psoriasis, our answer is usually to point them firmly back toward dermatology — because for this condition the conventional and biologic treatments are genuinely effective, and we won't oversell an unproven alternative. Where someone wants to understand the science, we explain where cell-based research honestly stands and why it isn't a replacement for the care that controls psoriasis today. Sometimes the most useful thing a clinic can do is tell you what not to spend your money on.

Common questions

Is psoriasis contagious? No. Psoriasis cannot be caught or passed to anyone by touch, sharing towels, or swimming — it's an immune-driven condition, not an infection ¹.

Is psoriasis curable? There's no cure, but it is very treatable. Most people can reach clear or near-clear skin and long quiet periods with the right plan, and treatment keeps improving ¹.

Is it the same as eczema? No — they're different conditions that can look similar. Psoriasis typically forms thicker, well-defined plaques with silvery scale, while eczema tends to be intensely itchy and less sharply bordered. A clinician can tell them apart.

Does stress cause psoriasis? Stress doesn't cause psoriasis, but it's a well-recognised trigger that can set off or worsen flares — which is why stress management is a sensible part of living with it ³.

Can diet or lifestyle help? Healthy habits — not smoking, moderating alcohol, maintaining a healthy weight, and good skin care — can support treatment and reduce flares, but they work alongside medical care rather than replacing it ³.

Key takeaway

Psoriasis is a common, chronic, immune-mediated condition in which skin cells renew far too fast and pile up into scaly plaques — and it can extend to the joints as psoriatic arthritis. It can't be cured, but it's highly treatable, with a clear ladder from creams and light therapy up to modern biologics. Regenerative cell therapy is not part of that proven toolkit; for psoriasis, well-evidenced dermatologic care comes first.