This is an old article that talks about a non permanent hypopigmentation of the BN, does anyone knows anything about it? ever tried this option?
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Introduction
Becker’s naevus is a special form of melanocytic naevus characterized by unilateral, asymptomatic, irregular, well defined, discrete and or confluent, pigmented macules over the shoulder region. It often coincides with the onset of adolescence and is more common in men. Patients seek medical advice only when the macules coalesce or the intensity of pigmentation increase and the vellus hairs over it become coarse and darker. Hitherto the dermatologists had nothing to offer as treatment for this condition. However in our practice we have come across a unique and interesting clinical situation, which reiterates the use of azelaic acid even for the treatment of Becker’s naevus.
Case report
Mr T K, a 25-year-old man presented with complaints of a large (20cm x 16cm) pigmented area involving his right shoulder extending on to his deltoid region. It had started as asymptomatic pigmented macules on his right scapular region 2 years ago, which was thought to be the pigmented variety of pityriasis versicolor and hence ignored without any treatment. But since a month the lesion became more pigmented and started spreading. Few hairs over this area became coarse and darker. On examination he was a healthy man weighing 60 kg. He had a Becker’s naevus over the right shoulder with irregular but well-defined borders. Several hypopigmented macules with branny scales were also seen on the upper part of the naevus, where the pigmentation had disappeared [Figure - 1]. The hypopigmented macules were due to pityriasis versicolor, as typical spores and hyphae of pityrosporum could be demonstrated in potassium hydroxide mounts of scales scraped from them. The loss of pigmentation of a naevus in the areas affected by pityriasis versicolor intrigued us. On further questioning he admitted that he developed these hypopigmented macules only since a month. The areas of the naevus affected by pityriasis versicolor seems to have lost the colour. He was reassured about the naevus and Whitfield’s ointment was prescribed for external application daily at bed time for 3 weeks. At the end of 3 weeks scaling had completely disappeared but the hypopigmentation was persisting.
He was re-examined again after 3 weeks. By then the previously hypopigmented areas have started developing pigmentation again.
Discussion
Pityriasis versicolor is the commonest fungal infection in the tropics. Though it can affect any part of the body the usual sites of involvement are the root of the neck, upper chest and back. Prior to the introduction of polyester dress materials it was indeed rare in people above the age of 60. The pigmented variety of pityriasis versicolor is seen only in the flexures of obese individuals. Rarely a dark skinned person develops generalized pityriasis versicolor imparting a lighter complexion in him. A small patch of uninvolved skin in him may be then mistaken for a nevoid hyperpigmentation.
The hypopigmentation of pityriasis versicolor is due to the competitive inhibition of the enzyme tyrosinase by certain dicarboxylic acids- notably azelaic acid ÂÂreleased from the surface lipids by the metabolic activity of the fungus. [1] Azelaic acid has been shown to inhibit DNA synthesis in melanoma cells. [2] Therefore it is now tried as local application (15-35% cream) for the treatment of lentigo maligna, [3] malignant melanoma [4] and even acne vulgaris. [5] A clinical trial of azelaic acid as a local medication for pigmented naevi is worth undertaking.
References Top
- Nazzaro-Porro M, Passi S, Balus L. The monoene fatty acids of human surface lipids and their relation to skin melanogenesis. Br J Dermatol 1977; 97: 16. Back to cited text no. 1
- Leibi H, Stingl G, Pehamberger H, et al. Inhibition of DNA synthesis of melanoma cells by azelaic acid. J Invest Dermatol 1985; 85: 417-22 Back to cited text no. 2
- Nazzaro-Porro M, Passi S, balus L, et al. Effect of dicarboxylic acids on lentigo maligna. J Invest Dermatol 1979; 72: 296-305. Back to cited text no. 3 [PUBMED]
- Nazzaro-Porro M, Passi S, Zina G, et al. Effect of azelaic acid on human malignant melanoma. Lancet 1980; 1 : 1109-11. Back to cited text no. 4 [PUBMED]
- Nazzaro-Porro M, Passi S, Picardo M, et al. Beneficial effect of 15% azelaic acid cream on acne vulgaris. Br J Dermatol 1983; 109: 41-8. Back to cited text no. 5 [PUBMED]
