The most effective way to treat psoriasis is: (1) to identify and remove the precipitating/aggravating factors; (2) to replace the defective skin barrier by cells with good barrier function. This means slowing down the epidermal turnover from forming defective barrier cells every 4 days to forming good barrier cells every 60 days.

(1) Identifying the Precipitating and Aggravating Factors:
The commonest precipitating factors are contact allergy reactions, which explains why psoriasis tend to localized to certain areas of the body. For example, the presence of psoriasis over the legs and ankles suggest allergy to antioxidants in elastic (‘stretch”) clothing e.g socks, stockings, slacks, shirts, gym clothing, etc. Psoriasis around the waist or lower back also suggests elastic allergy to elastic in the shorts/underwear etc. or to leather upholstery. Psoriasis over the back/shoulders may also be due to elastic in “stretch” blouses/shirts/bras. Allergy to a black/brown dye (paraphenylene diamine) should be considered if the feet (black socks) or the neck, shoulders, back (black hair dyes) are also involved. If the tops or sides of the feet or the soles are involved, allergies to glues, leather, etc., from the footwear are suspect. It is recommended that the skin of the foot is separated from the shoe by plastic wrap (Cling Wrap, press and seal) Allergic contact skin reactions require topical steroid preparations solutions for the scalp such as clobetasol solution, 1% hydrocortisone creams, usually mixed with an antifungal (Lotrimin cream/Ertaczo cream) for the tender areas (skin folds and skin), and steroid ointments (clobetasol ointment) for the trunk and limbs.

Another common aggravating factor for psoriasis on the trunk and limbs is bacterial overgrowth on the defective psoriatic skin. This is usually a bacterium (Staphylococcus aureus) which causes itching, and also causes the disease to spread. You should see your doctor for skin cultures and oral antibiotic treatment.

If the arm-pits are involved, deodorant allergies are suspect. If only the scalp is involved, the likely precipitating factor is overgrowth of the yeast (Pityosporum ovale) which feeds on the oils produced by the scalp. You should see your doctor for antifungal shampoos (ketoconazole shampoo or loprox shampoo) and possibly oral antifungal therapy.

If you have guttate (raindrop psoriasis), streptococcal infection is the cause. The likely sites of origin include the ears (keep your ears dry at all times), throat, sinuses, axilla, groin and perianal.

If you have problems identifying the precipitating factors, see your doctor or write to MadaleneHeng@PsoriaInfo.org. Dr. Heng’s suggestions are to assist you in identifying such factors, but cannot replace your doctor’s assessment and treatment. You must see and continue treatment with your doctor.


(2) Regrowth of the Defective Skin Barrier in Psoriasis
As a result of the defective gene on the 17th chromosome, psoriatic individuals are not able to switch off or lower the phosphorylase kinase levels induced by injury. This results in an overproduction of Ki67+ keratinocytes (i.e. keratinocytes capable of dividing and forming new cells) in the psoriatic epidermis, resulting in rapid epidermal turnover of once every 4 days in psoriatic epidermis compared to 60 days in normal skin. The rapid epidermal turnover in psoriasis results in formation of poor quality epidermal barrier resembling that of a jellyfish. The defective barrier not only allows further damage through water loss, but also promotes entry of allergens into the skin and promotes bacterial colonization and bacterial entry into the psoriatic skin. This bacterial overgrowth and “superinfection” causes persistence of the psoriatic process, and needs to be treated with oral antibiotics until the skin barrier is completely reformed.

Curcumin, a phosphorylase kinase inhibitor, decreases the Ki-67 population, and in doing so, slows down the rapid epidermal turnover to once in 60 days instead of every 4 days, resulting in regrowth of a good functional epidermal barrier. In a recent article (Sept 1 by Lisette Hilton) in the Dermatology Times, Dr Heng is quoted to say, “ In our patients, when the epidermal barrier in completely regrown as shown by the skin appearance returning to normal, it has been observed that all treatment, including curcumin may be stopped without recurrence of the psoriatic disease”. Since it takes 2 months to regrow 1 layer of the barrier, it usually takes 3-4 months for the complete barrier (10 layers) to reform. On the palms and soles with 200 layers, the barrier takes at least 6-12 months to reform.