Leukoderma

Components of pitch and coal tar produce cutaneous photosensitization skin eruptions usually are limited to areas exposed to ultraviolet light. " Most of the phototoxic agents will induce hypermelanosis of the skin if chronic photodermatitis is severe and prolonged, leukoderma may occur." Some oils containing PNAs have been associated with follicular and sebaceous gland changes, which commonly take the form of acne. ... 

Leukoderma was reported in two women engaged in degreasing metal parts with synthetic detergents containing polyoxyethylene (3-16), nonyl- or octylphenylether. Analysis revealed contamination with free alkylphe-nol, possibly octylphenol, or nonylphenol. Although a relationship between the cases of leukoderma and octyl- and nonylphenol exposure was suggested, it could not be confirmed. ... 

Ikeda M, Ohtsuji H, Miyahara S Two cases of leukoderma, presumably due to nonyl-or octylphenol in synthetic detergents. Ind Health 8 192-196, 1970... 

Furanocoumarlns have a number of scientifically interesting and even economically and medicinally Important actions. They are effectively used in human medicine in the treatment of vitiligo (skin depigmentation, leukoderma) ( ) and psoriasis (10,11), and have shown promise against certain other human maladies (12-15). Plants that contain furanocoumarlns are known to cause acute photosensltlzatlon (phytophotodermatltls) in man (2,16). 

Contraindications Concomitant disease states associated with photosensitivity (acute lupus erythematosus, porphyria, leukoderma of infectious origin), concomitant use of preparations with any internal or external photosensitizing capacity, hypersensitivity to trioxsalen or any component of the formulation... 

Leukoderma can occur, accompanied by normal melanocyte function but reduced phagocytic activity of the keratinocytes to eliminate the melanosomes (169). Depigmentation can occur at the site of injection of glucocorticoids. 

Three cases of severe lipoatrophy, one also with leukoderma, occurring within the same family after intramuscular injection of triamcinolone, suggested genetic susceptibility to this adverse effect (SEDA-3, 303). 

Bioulac P, Beylot C. Etude ultrastructurale d une leuco-dermie secondaire a une injection intraarticulaire de corti-coides. [Ultrastructural study of a leukoderma secondary to an intra-articular injection of corticoides.] Ann Dermatol Venereol 1977 104(12) 883-5. 

DNA (intercalation) (photosensitive yielding crosslinks) [dermatitic, mutagenic, phototoxic, PUVA therapy for leukoderma psoriasis]... 

There is a risk of sensitization from paraphenylenediamine when it is applied to the skin in combination with henna (4—6). This can result in contact allergic reactions as well as persistent contact leukoderma, as illustrated in five patients with paint-on henna tattoos (7). AH were positive on patch-testing with paraphenylenediamine. One developed erythema multiforme 4 weeks after the last application and the authors found no other causes of erythema multiforme. 

Leukoderma has been reported in two men from India who used 2% minoxidil lotion for 2-3 months to treat baldness (6). The depigmentation was localized to the scalp. Other possibilities of leukoderma were ruled out, as was vitiligo. There was repigmentation of the leuko-dermic area within 3 months of minoxidil withdrawal in both cases. 

Litt JZ, Beachwood, OH (personal case) (observation) (after 3 weeks of raloxifene, patient developed leukoderma over exposed areas of chest and forearms after sun exposure)... 

Eccrine squamous syringometaplasia (1997) Valks R+, Arch Dermatol 133, 873 Leukoderma... 

The fact that some substances sensitize human skin to light has been known at least since the time of the Pharaohs. The Egyptians used plant extracts from Ammi Majus, which contains psoralens, and sunlight to treat skin disorders such as leukoderma (vitiligo). In one of India s sacred books, Atharva Veda (1400 b.c. or earlier), photochemotherapy of leukoderma with extracts of Psoralea corylifolia, which contains furocoumarins, is carefully described. 

Panfuran acetate or acetylpanfuran, 3-acetylamino-6-(5-nitro-2-furyl-vinyl)-l,2,4-triazine Table 6.9), has been used for the treatment of acute tonsillitis. Although rapid clinical improvement was observed it must be remembered that results are difficult to assess. In the same study, black discoloration of the tongue was noted. Panfuran acetate has also been employed as an ointment. When used in concentrations of 0-03 per cent and 0-5 per cent, this formulation did not seem to cause any irritation (relevant to this point is that its precursor guanofuracin had caused leukoderma of the eyelids and therefore had to be withdrawn despite its good clinical efficacy). 

Contact urticaria, angioedema, and anaphylaxis Penetration of irritants through gloves Others endotoxin reactions, ethylene oxide, chemical leukoderma... 

Tan, C., W.Y. Zhu, and Z.S. Min. 2008. Co-existence of contact leukoderma and pigmented contact dermatitis attributed to Clematis chinensis Osbeck. Contact Dermat. 58(3) 177-178. 

Leukoderma is a general term for any pigmentary dilution, whether congenital or acquired, circumscribed or generalized (Ortonne et al. 1983). Occupational leukoderma will usually present as an acquired and circumscribed leukoderma. 

Hypopigmentation/hypomelanosis refers to a reduction in melanin content relative to the individual s normal skin. Depigmentation is a term implying loss of pre-existing melanin pigmentation (Mosher et al. 1993)- Vitiligo should be reserved for idiopathic or hereditary acquired leukoderma or depigmentation... 

Gellin 1990), while chemical leukoderma or toxic vitiligo, although not clearly defined, describes a depigmentation caused by the cutaneous exposure to chemicals that have direct, specific melanocytotoxic effects or suppress the capacity of melanocytes to produce melanin (Cummings and Nordlund 1995). 

Chemical leukoderma is a form of cutaneous pigment loss resembling vitiligo and is caused by exposure to a variety of chemicals that act by selective melanocyto-toxicity (Gellin and Maibach 1985). Most cases result from skin contact, but ingestion or inhalation of chemicals may also be factors. Chemical leukoderma has been referred to as occupational vitiligo, but a number of non-occupational cases have also been reported. 

A number of chemicals have been proposed to induce leukoderma by both human and animal in vivo studies, and also by experimental in vitro work (Table 7). The largest and best-studied group of chemicals are derivatives of phenol and catechol (Fig. 1). Hydroxylation of the 4-(para)-position and substitution of a non-polar alkyl side group in the i-position has been observed to increase effectiveness for depigmentation (Riley 1969). Alkyl phenols are used in the industrial setting as antioxidants or rust inhibitors. In commercial uses, they may be found in deodorants, disinfectants, germicides, insecticides, motor oils, oil additives, de-emulsifiers, paints, photographic chemi-... 

Table 5. Differential diagnosis of acquired and localized hypopigmentation (leukoderma). Adapted from Mosher et al. (1993) ...

Patch testing with various chemicals in the gloves confirmed that MBEH was the cause of the pigment loss. Leukoderma occurred at most positive patch test sites within 14 days to several months there was no direct correlation between intensity of patch test reactions and subsequent leukoderma. Hydroquinone (HQ) was present as an impurity at less than one percent and was not a factor in the leukoderma. Several months after workers discontinued wearing the gloves, partial perifollicular repigmentation was noted. 

Around the same time, McNally (1939) reported similar cases of depigmentation in 34 tannery workers, initially involving the hands and arms. The leukoderma was associated with the use of a new brand of rubber gauntlet gloves, which was found to contain the same antioxidant, MBEH, as well as unchanged HQ. 

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