Psoriasis vs. Candidiasis

Overview

Psoriasis is a chronic inflammatory condition mainly affecting the skin, with occasional involvement of joints, nails and mucous membranes. Candidiasis, on the other hand, is a fungal infection caused by the yeast species, Candida albicans.
The two conditions present as itchy, scaly patches with overlapping similarities in presentation but with some clear-cut differences.

Causes

Psoriasis has a complex etiology, primarily involving an interaction between keratinocyte skin cells and T-lymphocyte white blood cells to produce an inflammatory response that leads to accelerated cellular turnover of skin cells, with flaking and formation of itchy or burning, raised skin patches. It is not an infective process and is not contagious.

A variant of psoriasis, inverse psoriasis affects skin folds such as those under the breasts and the groin--the same areas that are usual sites for candidiasis.
It will take a close look and thorough evaluation in a previous case of psoriasis to differentiate the two.

Candidiasis is caused by an overgrowth of the fungus Candida albicans, with a resultant local tissue reaction and inflammation that produces characteristic itching and burning. It is classically found in moist areas of the skin such as the groin, skin folds, external genitalia and the mouth. It can be transmitted from person to person by close, intimate contact.

Predisposing Factors

Psoriasis has been postulated to have a genetic predisposition in some cases for those with a family history of an overactive immune system.

The predominant feature in candidiasis is one of a lowered immunity, either locally in the regions that have undue wetness, or systemically due to such immune-depressing factors as HIV/AIDS, diabetes mellitus or immune suppressant therapy. There is no family history directly linked to this condition.

Diagnosis

Psoriasis is diagnosed by skin biopsy with typical cytological findings. Skin scrapings from the lesions of candidiasis typically show the growing hyphae after dissolution in potassium hydroxide solution.

Treatment

Psoriasis requires a multipronged approach of treatment based on its multifaceted pathology, but the hallmark of effective treatment is immune-suppressant therapy.

Candidiasis is treated by antifungals and worsened by immune suppressant therapy.

Coexisting Conditions

Psoriasis is linked with certain other autoimmune diseases like insulin-dependent diabetes mellitus, which happens to be a predisposing factor for candidiasis. Thus, there could be a coexistence for those individuals with both psoriasis and diabetes mellitus.

Drug therapy for psoriasis also depresses immunity, predisposing the patient to candidiasis. There could be coexistence in those patients on long-term immunosuppressant therapy.