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Psoriasis is a recurring, non-contagious skin disorder that is characterised by raised, thickened patches of red skin covered with silvery white scales.



Psoriasis originates in the immune system.  The key immune system trigger is the activation of T-cells, a type of white blood cell.  Once activated, these cells release cytokines, which are the chemicals used by the immune system to communicate messages.  In psoriasis, these cytokines tell skin cells to multiply and mature at an accelerated  rate, resulting in thickening of the skin.  The redness results from the increased blood supply required for the increased growth of cells.


Aggravating factors


Psoriasis is worsened by stress, alcohol and certain medications 


Comorbidities associated with psoraisis

We know now that the low grade inflammation in psoriasis impacts organs beyond the skin. Below is a list of the most common commodities. 


 Psoriatic arthritis

 Inflammatory bowel disease

 Psychological and psychiatric disorders



 Metabolic syndrome and its components

 Cardiovascular diseases


 Nonalcoholic fatty liver disease


 Sleep apnea

 Chronic obstructive pulmonary disease


 Parkinson's disease

 Celiac disease

 Erectile dysfunction

Related to lifestyle

Smoking habit



Related to treatment


(acitretin and cyclosporine)

Nephrotoxicity (cyclosporine)

 Hypertension (cyclosporine)

 Hepatotoxicity (methotrexate, leflunomide and acitretin)

 Skin cancer (PUVA)


Types of Psoriasis


  • Plaque Psoriasis 

        common type in which there are large patches of red skin with silvery-white scales.

  • Guttate Psoriasis 

        small patches, usually less than 1cm in diameter.

  • Inverse Psoriasis 

        Psoriasis occuring in the body folds such as armpits and groins

  • Eyrthrodermic Psoriasis

        almost the entire body is red with Psoriasis

  • Pustular Psoriasis

        small pustules (pus filled areas) are scattered throughout the body

  • Nail Psoriasis

  • Psoriatic Arthritis

Ref: Oliveira Mde F, Rocha Bde O, Duarte GV. Psoriasis: classical and emerging comorbidities. An Bras Dermatol. 2015 Jan-Feb;90(1):9-20..

Sites of Psoriasis


Common areas of involvement include:


flexures - armpits, groins and gluteal cleft (groove between buttocks).  Type of psoriasis where the flexures are predominantly involved is called flexural psoriasis.

Nail changes in Psoriasis



Total destruction of all nails in psoriasis



Classical nail pitting in psoriasis



Psoriasis of the nail with arthritis of the joint



textural changes on the bases of the nails in Psoriasis

The nail changes of psoriasis cannot be distinguished from a fungal infection by just looking at the nails. For this reason, nail clippings need to be sent to the laboratory for analysis. Treatment for fungal infection should be administered only if the nail shows fungus.

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Ixekizumab (Copellar)

The biologics are a new line of psoriasis treatments which target specific parts of the immune system. 


They therefore are expected to have fewer side effects than existing treatments. 


Unlike other systemic drugs, the biologics are administered by injection.

The cost of a biologic medication ranges from around R1500 to R30000 per injection, the cost being largely due to the method of manufacture of the medication, the laboratory that manufactures it and how long it has been on the market.


Medical aid societies differ in their cover for this medication. Please check with your medical aid if you have cover for this. Alternatively, you have the option of self funding.

The following biologics are currently available in South Africa

Biologics diagram



Topical (Applied on the skin)


  • 2% Ung acid sal
    this medication peels the thickened skin and restores normal skin thickness

  • Tar 
    reduces the rapid growth of skin cells

  • Dithranol 

  • Calcipotriol / Betamethasone combination (Dovobet) 
    effective in restoring normality in psoriasis areas

  • Clobetasol shampoo (Clobex). This is a strong topical steroid preparation and its use on the scalp must be limited to 2 weeks at a time.


Ultraviolet light



narrow band UVB

Excimer laser/light

Home care phototherapy

Oral treatments


  • Methotrexate

  • Acitretin (Neotigason)

  • Cyclosporin

New treatments for Psoriasis (Biologics)


  • Infliximab (Revellex/Remicaide)


Infliximab is given intravenously in the doctors office.  Initial treatment is administered at weeks 0,2 and 6.  Thereafter, treatment is given at 8 week intervals.  (For more information on Infliximab - also known as Revellex or Remicaide - please click here, bearing in mind that the cost support does not apply to South Africa)

  • Etanercept (Enbrel)


This biologic has been approved for the treatment of psoriatic arthritis and is undergoing final testing in patients with skin psoriasis.  Intitial studies have shown that half the patients achieved more than 70% clearance and that 70% of patients achieved 50% clearance.  It is administered by subcutaneous injection twice weekly.  Patients can be taught to administer the treatment at home, much like injecting insulin at home for diabetes. (For more information on Enbrel, please click here)


  • Adalimumab (Humira)


Self injected subcutaneously, 80mg followed by 40mg a week later, then 40mg every fortnight. (More information)

ANTI IL12/23

  • Ustekinumab (Stelara)


Given by subcutaneous injection at week 0, 4 then once every 3 months. Patients weighing less that 100kg get 45mg and those over 100kg receive 90mg per injection. (For Ustekinumab use in psoriasis, please click here. Remember that special offers on this website applies to USA only)


  • Secukinumab (Cosentyx)

Secukinumab is administered on Week 0, 1, 2, 3, 4 then every 4 weeks. The mode of action is different from the other biologics. It is given by subcutaneous injection. In clinical trials, the majority of people taking COSENTYX 300 mg were clear or almost clear at 12 weeks. Approximately 8 out of 10 people saw 75% skin clearance. Approximately 6 out of 10 people saw 90% skin clearance. Many who saw results at 1 year maintained them at 5 years. 

  • Ixekizumab (Copellar)

A recently launched IL17 drug from Lilly laboratories. The dose of Copellar is 160mg (2 injections of 80mg) on week 0, the 80 mg (1 injection) every 2 weeks for 12 weeks, then 80mg every 4 weeks. In addition to skin psoriasis, it can be used for psoriatic arthritis. It shows high clearance rates in psoriasis. For those interested in the statistics: of 206 patients at Week 60, PASI 75/90/100 responses were 94.7%, 85.0% and 62.1%, respectively, and at year 5 were 90.3%, 71.3% and 46.3%, respectively. Read more


  • Guselkumab (Tremfya)

Launched in October 2020, Tremfya is one of the most recent biologic to be available. It is administered at a dose of 100mg on Weeks 0, 4 and 8, thereafter every 8 weeks.  In clinical studies at week 16, 7 out of 10 patients with moderate to severe plaque psoriasis saw 90% clearer skin. In a clinical study, nearly 9 out of 10 patients who saw 90% clearer skin at week 28 maintained it at week 48. 

Side Effects of Biologics

1.  Worsening of TB or new onset TB.  All patients are screened for TB before starting a biologic.  The tests include a Chest Xray and a Mantoux test (small injection on the forearm. The results are read 3 days later). An alternative TB test is called the Quantiferon test. This is a blood test.

2.  Worsening of heart failure. Let the doctor know if you have any swelling of the legs or shortness of breath.

3.  Peripheral neuritis - tingling of the fingers and toes.

4.  Lumps / bumps or cancers.  These are looked for at every visit and are rare consequences of suppressing the immune system, although biologics do not fall under the traditional category of immune suppressants.


The Psoriasis Advisory Board of South Africa has put together a set of guidelines for the management of Psoriasis.  This has been published in the South African Medical Journal (SAMJ).

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Psoralen is taken orally 2 hours before exposure to UVA light. Treatment is administered three times a week for 7 weeks - a total of 21 treatments. the use of PUVA is declining throughout the world and has now given way to Narrow band UVB.


Further reading


New Zealand Dermnet


Additional resources

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