Itchy scaling rash

A waxing and waning rash with fine scale is classic for tinea versicolor (TV). A potassium hydroxide (KOH) prep with Swartz-Lamkins stain confirmed the presence of the spaghetti-and-meatballs pattern of Malassezia furfur (MF).

TV is a skin infection caused by M furfur. TF is notorious for the variety of colors that are seen clinically, including hyperpigmentation, as seen in a recent installment in this column.¹ It can also appear as hypopigmented lesions or tan macules and patches with fine scale, as was seen in this patient. Hypopigmentation is often more pronounced on sun-exposed areas of the body. The MF produces azelaic acid. The azelaic acid blocks tyrosinase, which hinders melanocyte function and leads to hypopigmentation.² As a result, areas of skin that are affected by TV do not tan as much as the surrounding skin, making the lesions more pronounced.

First line treatment of TV includes topical antifungal preparations, such as the “azoles” (eg, clotrimazole, ketoconazole, miconazole) twice daily for 2 to 4 weeks. However, the large surface areas involved would require a large amount of these antifungal preparations that come in relatively small tubes. Thus, for many years, clinicians have turned to economical over-the-counter dandruff shampoos with either selenium sulfide or zinc pyrithione that provide excellent results. These shampoos are applied to the entire trunk at full strength, allowed to dry, and then washed off later following various timed protocols. If topical therapy is not successful, or if there is a recurrence, systemic antifungal medications are used. Oral options include fluconazole 200 mg to 300 mg orally once a week for 2 weeks and itraconazole 200 mg orally once a day for 7 days.³ Ketoconazole is avoided as a systemic antifungal (except in life-threatening situations) due to its higher rate of liver dysfunction.

This patient was instructed to apply full-strength selenium sulfide shampoo to his entire trunk in the evening, allow it to dry, then wash it off the next morning and repeat in 1 week. An alternate regimen is to leave it on for 1 hour before washing and repeat daily for 1 week. At the patient’s follow-up appointment a month later, the rash and itching had resolved.

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Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.

A waxing and waning rash with fine scale is classic for tinea versicolor (TV). A potassium hydroxide (KOH) prep with Swartz-Lamkins stain confirmed the presence of the spaghetti-and-meatballs pattern of Malassezia furfur (MF).

TV is a skin infection caused by M furfur. TF is notorious for the variety of colors that are seen clinically, including hyperpigmentation, as seen in a recent installment in this column.¹ It can also appear as hypopigmented lesions or tan macules and patches with fine scale, as was seen in this patient. Hypopigmentation is often more pronounced on sun-exposed areas of the body. The MF produces azelaic acid. The azelaic acid blocks tyrosinase, which hinders melanocyte function and leads to hypopigmentation.² As a result, areas of skin that are affected by TV do not tan as much as the surrounding skin, making the lesions more pronounced.

First line treatment of TV includes topical antifungal preparations, such as the “azoles” (eg, clotrimazole, ketoconazole, miconazole) twice daily for 2 to 4 weeks. However, the large surface areas involved would require a large amount of these antifungal preparations that come in relatively small tubes. Thus, for many years, clinicians have turned to economical over-the-counter dandruff shampoos with either selenium sulfide or zinc pyrithione that provide excellent results. These shampoos are applied to the entire trunk at full strength, allowed to dry, and then washed off later following various timed protocols. If topical therapy is not successful, or if there is a recurrence, systemic antifungal medications are used. Oral options include fluconazole 200 mg to 300 mg orally once a week for 2 weeks and itraconazole 200 mg orally once a day for 7 days.³ Ketoconazole is avoided as a systemic antifungal (except in life-threatening situations) due to its higher rate of liver dysfunction.

This patient was instructed to apply full-strength selenium sulfide shampoo to his entire trunk in the evening, allow it to dry, then wash it off the next morning and repeat in 1 week. An alternate regimen is to leave it on for 1 hour before washing and repeat daily for 1 week. At the patient’s follow-up appointment a month later, the rash and itching had resolved.

‌

Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.

A waxing and waning rash with fine scale is classic for tinea versicolor (TV). A potassium hydroxide (KOH) prep with Swartz-Lamkins stain confirmed the presence of the spaghetti-and-meatballs pattern of Malassezia furfur (MF).

TV is a skin infection caused by M furfur. TF is notorious for the variety of colors that are seen clinically, including hyperpigmentation, as seen in a recent installment in this column.¹ It can also appear as hypopigmented lesions or tan macules and patches with fine scale, as was seen in this patient. Hypopigmentation is often more pronounced on sun-exposed areas of the body. The MF produces azelaic acid. The azelaic acid blocks tyrosinase, which hinders melanocyte function and leads to hypopigmentation.² As a result, areas of skin that are affected by TV do not tan as much as the surrounding skin, making the lesions more pronounced.

First line treatment of TV includes topical antifungal preparations, such as the “azoles” (eg, clotrimazole, ketoconazole, miconazole) twice daily for 2 to 4 weeks. However, the large surface areas involved would require a large amount of these antifungal preparations that come in relatively small tubes. Thus, for many years, clinicians have turned to economical over-the-counter dandruff shampoos with either selenium sulfide or zinc pyrithione that provide excellent results. These shampoos are applied to the entire trunk at full strength, allowed to dry, and then washed off later following various timed protocols. If topical therapy is not successful, or if there is a recurrence, systemic antifungal medications are used. Oral options include fluconazole 200 mg to 300 mg orally once a week for 2 weeks and itraconazole 200 mg orally once a day for 7 days.³ Ketoconazole is avoided as a systemic antifungal (except in life-threatening situations) due to its higher rate of liver dysfunction.

This patient was instructed to apply full-strength selenium sulfide shampoo to his entire trunk in the evening, allow it to dry, then wash it off the next morning and repeat in 1 week. An alternate regimen is to leave it on for 1 hour before washing and repeat daily for 1 week. At the patient’s follow-up appointment a month later, the rash and itching had resolved.

‌

Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.