What triggers Psoriasis

Psoriasis is a chronic inflammatory skin disorder and whilst the exact causes of psoriasis have yet to be discovered, the immune system and genetics are known to play major roles in its development. The immune system is somehow mistakenly triggered, which speeds up the growth cycle of skin cells among other immune reactions1

Researchers show that whether a person develops psoriasis or not may depend on a “trigger”2. These Primary Triggers activate the condition.

Possible Primary triggers include:

Koebner Phenomenon – Skin Injury e.g. animal bites, burns, electrodesiccation, excoriation, freezing, friction, gunshot wounds, insect bites, lacerations, nail manicuring, Poor fitting shoes, pressure, shaving, surgical grafts, surgical incision, tape stripping, thumb sucking, x-rays, sunburn, tattoos (injury).

Stress – anxiety, depression, psychological illnesses e.g. Post-Traumatic Stress Disorder.

Certain medicines:-

  • Anti-malarial– e.g. Doxycycline, chloroquine
  • Lithium– depression or psychiatric disorders
  • ACE Inhibitors– High blood pressure medication
  • Anti-inflammatory medicine – e.g. ibuprofen or Indomethacin
  • Beta blockers– taken by patients with heart failure
  • Corticosteroid– Prescribed for a variety of health conditions. Sudden discontinuation of relatively high doses can be a trigger

Infections  in some people, usually children and young adults, a form of psoriasis called guttate psoriasis develops after a streptococcal throat infection (note: most people who have streptococcal throat infections will not develop psoriasis), upper respiratory infections such as such as streptococcal pharyngitis or sinusitis. People with weakened immune systems; such as HIV patients, are more susceptible to psoriasis.

There are also a number of Secondary Triggers, and these exacerbate the condition once it has been activated, and will continue to worsen the condition. They are:-

  • Consumption of alcohol
  • Smoking
  • Chemical exposure e.g. household or work cleaning products (chlorine based), flea/cockroach ‘bombs’, passive cigarette exposure, hairdressing products e.g. dyes, paints, lacquers, thinners, insecticides, pesticides, herbicides, nickel and leather dyes, nickel etc.
  • Dehydration
  • Constipation or diarrhea
  • Hormones
  • Weather – exposure to cold
  • Adverse food (acidic / diuretics) – tomatoes, chilli, capsicums, citrus, berries, pineapples, soft drinks (carbonated), sweets (chocolate, cakes, cream, ice-cream), tea, coffee, red meat, food additives, preservatives to name a few.

Not all psoriasis sufferers will react to all of the above triggers, so the best thing to do is to record consumption of foods, liquids etc., how you slept, what stresses you were under and any exposure to chemicals and other environmental triggers and at the same time monitor your symptoms e.g. increases itch, irritability, new lesions or worsening of existing lesions etc. Note that some triggers e.g. skin injuries may not show a flare-up up for up to 10 to 14 days after a triggering event, so if you noticed that you were bitten by mosquitoes or insects record it with the date and then take note of any subsequent delayed flare ups.


  1. Višnja Milavec-Pureti? et al.; Drug Induced Psoriasis; Acta Dermatovenerol Croat 2011;19(1):39-42
  2. Kuchekar A.B. et al.; Psoriasis: A comprehensive review; Int. J. of Pharm. & Life Sci. (IJPLS), Vol. 2, Issue 6: June: 2011, 857-877 857