A REVIEW OF THE CURRENT STATUS OF TINEA VERSICOLOR IN SOME PARTS OF NIGERIA

Tinea versicolor (i.e. Pityriasis versicolor) is a common superficial fungal infection. Patients with this disorder often show symptoms of hypopigmented, hyperpigmented, or erythematous macules on the trunk and proximal upper extremities. Unlike other disorders utilizing the term Tinea (e.g., Tinea pedis, Tinea capitis), Tinea Versicolor is a very common infection which is very difficult to cure but yet mostly ignored. Tinea versicolor is caused by the dimorphic, lipophilic organisms in the genus Malassezia, formerly known as Pityrosporum. The yeast causing the infection very often lives harmlessly in the skin of most adults. Among the symptoms of Tinea is a mild form of eczema that produces mild, patchy lightening of the face, shoulders, or torso. Its distribution is normally parallel to that of the sebaceous glands, with higher occurrence on the thorax, back and face. The infection has worldwide occurrence, its frequency is variable and depends on different climatic, occupational and socio-economic conditions. Tinea versicolor responds well to medical therapy, but recurrence is common and long-term prophylactic therapy may be necessary. The pathophysiology, clinical features, diagnosis, and management as well as prevention of Tinea versicolor were reviewed in this paper. Keywords; Infection, pathophysiology, diagnosis, prevalent, treatment INTRODUCTION Tinea versicolor also known as dermatomycosis furfuracea, Pityriasis versicolor and Tinea flava [1] is a condition characterized by a skin eruption on the trunk and proximal extremities. Recent research has shown that the majority of Tinea versicolor is caused by the Malassezia globosa fungus, although Malassezia furfur is also responsible for a small number of cases [2]. These yeasts are normally found on the human skin and only become troublesome under certain circumstances, such as a warm and humid environment, although the exact conditions that cause initiation of the disease process are poorly understood [3]. The condition Pityriasis versicolor was first identified in 1846 [4]. Versicolor comes from the Latin word “versāre” to change colour. Skin infections are very common in childhood worldwide and between 49 80.4% of African school children are affected [5]. It has been observed to be common in adolescent and young adult males in hot climates [6]. The prevalence of fungal skin infection is about 20% among the American populations at any given time in addition to Ethiopia, 49.2% and Taiwan, 28.2% [7]. Skin infections have been reported to be a major problem in Tanzania where about 34.7% of the International Journal of Scientific Engineering and Applied Science (IJSEAS) – Volume-2, Issue-1, January 2016 ISSN: 2395-3470 www.ijseas.com 202 rural populations have skin diseases [8],[9]. In Nigeria, the prevalence rate is about 40.4% among pupils in primary schools [10]. Clinical investigations have shown that, dermatophytosis of Tinea versicolor and Tinea corporis are responsible for more than 15% of all skin infections in Nigeria [11]. An increase in the prevalence of T. versicolor, among others, was once recorded in the University College Hospital (UCH), Ibadan, between 1994 and 1998 [11]. Poor socioeconomic status was identified as the major cause of skin infections in the developing countries [12]. T. versicolor (Synonym Pityriasis versicolor) is a common, innocuous and chronic fungal infection of the stratum corneum caused by the dimorphic yeast Malassezia furfur. The synonyms Pityrosporum ovale and P. orbiculare were used previously to identify the causal organism. The common sites for the appearance of symptoms on the human body include the chest, neck, back, upper and lower arms. The infection is associated with persistent patches of discoloured skin portions, sharp edges, fine scales and sometimes accompanied by body itching. The predisposing factors to infection include a warm, humid environment, excessive sweating, occlusion, high plasma cortisol levels, immunosuppression, malnourishment and genetically determined susceptibility [13]. Most infections of dermatophytosis are usually treated with drugs e.g. Clotrimazole, Ketoconazole, Fluconazole, Itraconazole, etc.[14]. These drugs are relatively expensive and mostly unaffordable by people with low socio-economic status, who invariably form the bulk of people with skin infections. Both rural and urban residents in the tropical regions, with pronounced Tinea infections, usually resort to herbal remedies that are sourced locally from their native environments. Herbal preparations such as poultices, ointments and soaps have been applied by 65% of patients with eczema, seborrhoiec dermatitis, impetigo, T. capitis and scabies before attending orthodox hospitals [15]. [16] and[17] reported that leaf juice and decoctions of S. alata are used in the treatment of ringworm and other skin diseases in many parts of Nigeria. Among several plant species used in the treatment of skin infection locally without any reported risk or allergic reaction is S. alata (L) Roxb-Caesalpinaceae (formally Leguminosae). Pityriasis versicolor (PV), also known as Tinea versicolor, is one of the most common superficial fungal infections worldwide, particularly in tropical climates. PV is difficult to cure and the chances for relapse or recurrent infections are high due to the presence of Malassezia in the normal skin flora. This review focuses on the clinical evidence, treatment and contemporary status of Tinea versicolor in some countries. The aim of this study is to review the status of Tinea versicolor in some parts of the world. Pathophysiology Tinea versicolor is caused by the dimorphic, lipophilic organisms in the genus Malassezia, formerly known as Pityrosporum. Eleven species are recognized within this classification of yeasts, of which Malassezia globosa and Malassezia furfur are the predominant species isolated in Tinea versicolor [18],[19]. Malassezia is extremely difficult to propagate in laboratory culture and is culturable only in media enriched with C12to C14-sized fatty acids. Malassezia is naturally found on the skin surfaces of many animals, including humans. Indeed, it can be isolated in 18% of infants and 90-100% of adults. The organism can be found on healthy skin and on skin regions demonstrating cutaneous disease. In patients with clinical disease, the organism is found in both the yeast (spore) stage and the filamentous (hyphal) form. Factors that lead to the conversion of the saprophytic yeast to the parasitic, mycelial morphologic form includes genetic predisposition; Warm, humid environments, immunosuppression, malnutrition International Journal of Scientific Engineering and Applied Science (IJSEAS) – Volume-2, Issue-1, January 2016 ISSN: 2395-3470 www.ijseas.com 203 and Cushing syndrome. Human peptide cathelicidin LL-37 plays a role in skin defence against this organism. Even though Malassezia is a component of the normal flora, it can also be an opportunistic pathogen. The organism is considered to be a factor in other cutaneous diseases, including Pityrosporum folliculitis, confluent and reticulate papillomatosis, seborrheic dermatitis, and some forms of atopic dermatitis. Malassezia species have also been shown to be a pulmonary pathogen in patients with immunosuppression due to stem cell transplantation [20]. Causes of Tinea versicolor Tinea versicolor is caused by yeast called Malassezia furfur that normally live on the skin of most adults without causing problems. It exists in two forms, one of which can cause patches of discoloured slightly scaly skin. Factors that induce the disease are poorly understood, but high humidity and immune changes may play roles [20]. Most people with this condition are perfectly healthy. Because the Tinea versicolor fungus is part of the normal adult skin flora, this condition is not contagious. It often recurs after treatment, but usually not right away, so that treatment may need to be repeated only every year or two. Tinea versicolor patches that are brown or reddish-brown go right away after treatment. This fungus produces a chemical, which seems to inhibit the normal production of pigment in the skin resulting in areas of lighter skin. It may take several months for overall colour to even out. It always eventually does. Tinea versicolor does not leave permanent skin discoloration. M. furfur is now the most commonly accepted name for the organism causing Tinea versicolor. Thus, P. orbiculare, P. ovale and M. ovalis are synonyms for M. furfur. Despite disagreement about the names, Tinea versicolor results from a shift in the relationship between a human and a resident yeast flora. Yeasts of the genus Malassezia are known to be members of the skin microflora of human and other warm-blooded vertebrates [21],[22]. These lipophilic yeasts are associated with various human diseases, especially Pityriasis versicolor, a chronic superficial scaling dermatomycosis [23]. The genus of Malassezia has undergone several taxonomic revisions [24]. Later, [25] discovered that there were indeed multiple species which they reclassified and named the genus as Malassezia with several distinct species. Currently there are 11 recognised species viz: 1. M. furfur, [18],[26] 2. M. pachydermatis, 3. M. sympodialis [27] 4. M. globosa [28],[29],[30],[31][22] 5. M. obtuse 6. M. restricta 7. M. slooffiae [25] 8. M. dermatis 9. M. equi 10. M. nana [32],[33] 11. M. japonica[32]