Gold ring induced depigmentation.

Sir,

Contact depigmentation though commonly occupational, has been reported to occur following non occupational contact. Depigmentation in Asians, especially those who are dark skinned, is a source of great mental stress. Gold has been associated with causing various dermatitis.

A thirty one year old male doctor presented with depigmentation on both ring fingers for the last 8 months. The depigmentation had started on the right ring finger at the site of marriage ring. On transferring the ring to the left ring finger, similar depigmentation was observed 2 months after transfer of ring. There was no prior history of itching, vesicles or oozing. Patient gave a history that he used to remove the ring before bathing every day. On examination depigmentation was noticed on the sides of both the ring fingers which corresponded to contact with the gold ring [Figures 1 and 2]. There were no lesions elsewhere on the body. Patch testing with gold from standard series was done which was negative and no depigmentation was noticed even at the end of 8 months of follow up.

Figure 1

Depigmentation noticed at the side of ring finger of right hand

Figure 2

Depigmentation noticed at the side of ring finger of left hand

Contact depigmentation (syn. contact vitiligo, contact leucoderma) is commonly referred to as occupational leucoderma or occupational vitiligo in view of its occurrence predominantly following workplace exposure. However various non-occupational substances have been incriminated such asbindis, shoes, adhesive tapes, wrist watch straps, rubber products and germicidal phenolic detergents.[1]

Numerous chemicals have been associated with contact depigmentation like cresols, phenols, hydroquinone, p-tert butyl phenol formaldehyde resin, monobenzyl ether of hydroquinone (MBEH), acrylates, cinnamates, aldehydes, paraphenylenediamine (PPDA), alta, physostigmine, rubber and polyvinyl plasticizers.[2]

Gold which was the allergen of the year in 2001, has been associated with various dermatitis like allergic contact dermatitis, lichenoid contact dermatitis, systemic contact dermatitis and non-eczematous persistent papular eruptions.[23]

Gold ring dermatitis has been reported to occur either primarily from allergy to gold or secondary to the accumulated detergents or corrosive action of salts on the ring.[2]

Various theories have been proposed for contact depigmentation like direct toxic effect, free radical formation, inhibition of synthesis or transfer of melanocytes and post inflammatory hypopigmentation.

Non-eczematous variants of contact dermatitis are well known and can present as pigmentary alterations, purpura, erythema multiforme, lichen planus etc., without the typical features of eczema such as itching and vesiculation.[2] Patch testing with suspected allergens is the only way to clinch the diagnosis. In our patient the patch test with gold was negative. Vitiligo was also ruled out, in view of absence of lesions elsewhere on the body.

We postulate that in our case the depigmentation is subsequent to the repeated trauma caused secondary to removing the ring everyday, as the depigmentation was noted only at the sides of the fingers where friction occurs on removing and putting the ring.