18_319_334* 05.11.2005 10:30 Uhr Seite 319 Chapter 18 Pigmented Contact Dermatitis 18 and Chemical Depigmentation Hideo Nakayama Contents ca, often occurs without showing any positive mani- 18.1 Hyperpigmentation Associated festations of dermatitis such as marked erythema, with Contact Dermatitis . 319 vesiculation, swelling, papules, rough skin or scaling. 18.1.1 Classification . 319 Therefore, patients may complain only of a pigmen- 18.1.2 Pigmented Contact Dermatitis . 320 tary disorder, even though the disease is entirely the 18.1.2.1 History and Causative Agents . 320 result of allergic contact dermatitis. Hyperpigmenta- 18.1.2.2 Differential Diagnosis . 323 tion caused by incontinentia pigmenti histologica 18.1.2.3 Prevention and Treatment . 323 has often been called a lichenoid reaction, since the 18.1.3 Pigmented Cosmetic Dermatitis . 324 presence of basal liquefaction degeneration, the ac- 18.1.3.1 Signs . 324 cumulation of melanin pigment, and the mononucle- 18.1.3.2 Causative Allergens . 325 ar cell infiltrate in the upper dermis are very similar 18.1.3.3 Treatment . 326 to the histopathological manifestations of lichen pla- 18.1.4 Purpuric Dermatitis . 328 nus. However, compared with typical lichen planus, 18.1.5 “Dirty Neck” of Atopic Eczema . 329 hyperkeratosis is usually milder, hypergranulosis 18.2 Depigmentation from Contact and saw-tooth-shape acanthosis are lacking, hyaline with Chemicals . 330 bodies are hardly seen, and the band-like massive in- 18.2.1 Mechanism of Leukoderma filtration with lymphocytes and histiocytes is lack- due to Chemicals . 330 ing. 18.2.2 Contact Leukoderma Caused Mainly by Contact Sensitization . 332 A lichenoid reaction is considered to be a scaled- down type-IV allergic reaction of the lichen planus References . 332 type, based on positive patch test reactions in pa- tients and negative reactions in controls, as in ordi- nary allergic contact dermatitis. An increase in melanin pigment in keratinocytes is noted after allergic contact dermatitis, presumably 18.1 Hyperpigmentation Associated caused by hyperfunction of melanocytes, but the with Contact Dermatitis same phenomenon is also seen with irritant contact dermatitis.When sodium lauryl sulfate,a typical skin 18.1.1 Classification irritant, was repeatedly applied on the forearms of Caucasians, the number of epidermal melanocytes Hyperpigmentation associated with contact derma- was observed to almost double, suggesting hyperpla- titis is classified into three categories: (1) hyperpig- sia, hypertrophy, and increased function [1]. mentation due to incontinentia pigmenti histologica; The pathological processes involved in the third (2) hyperpigmentation due to an increase in melanin form of hyperpigmentation with contact dermatitis, in the basal layer cells of the epidermis, i.e., basal me- purpuric dermatitis, have not yet been clarified. Shii- lanosis; and (3) hyperpigmentation due to slight take mushroom, very commonly eaten in Asia, has hemorrhage around the vessels of the upper dermis, been known to produce a transient urticarial derma- resulting in an accumulation of hemosiderin, such as titis with severe itching, which results in a purpuric in Majocchi–Schamberg dermatitis. scratch effect, when insufficiently cooked. This is It is easy to understand that when the grade of thought to be due to toxic substances in the mush- contact dermatitis is more severe, or its duration room unstable to heat, and the pigmentation due to longer, the secondary hyperpigmentation following purpura is not caused by hypersensitivity [2].As with dermatitis is more prominent. However, the first type other forms of dermatitis, accompanying capillary mentioned above, incontinentia pigmenti histologi- fragility results in purpura. Some cases are associat- 18_319_334* 05.11.2005 10:30 Uhr Seite 320 320 Hideo Nakayama ed with contact hypersensitivity to rubber compo- allergens from textiles, soaps or washing nents or textile finishes, but in many cases the causes powders for textiles. Successive contact are not known. with small amounts of allergens destroys basal layer cells of the epidermis, resulting in melanin accumulation in the upper 18.1.2 Pigmented Contact Dermatitis dermis for a long time. Treatment entails finding out the contact allergens, and 18.1.2.1 History and Causative Agents avoiding them for a long time. Core Message Pigmented contact dermatitis was first reported by í Pigmented contact dermatitis on the Osmundsen in Denmark in 1969. In 8 months he had covered area cannot be cured by the 120 patients, 7 of whom showed a pronounced and application of corticosteroid ointments, bizarre hyperpigmentation. In 4 of these 7 cases con- even though it is a result of contact tact dermatitis preceded the hyperpigmentation, Table 1. The main contact sensitizers producing secondary hyperpigmentation Name Chemical structure Purpose Patch test concentration and base Tinopal CH3566 Optical whitener in 1% pet. washing powder Naphthol AS Dye for textile 1% pet. Benzyl salicylate Fragrance 5–1% pet. Hydroxycitronellal Fragrance 5–1% pet. D &C Red 3 and brilliant Pigment for cosmetics 1% pet. lake red R 18 Phenyl-azo-2-naphthol Impurity 0.1% pet. (PAN) D & C Yellow 11 Pigment for cosmetics 0.1% pet. Ylang-ylang oil Fragrance, incense 5% pet. dehydrodiisoeugenol 18_319_334* 05.11.2005 10:30 Uhr Seite 321 Contact Dermatitis and Chemical Depigmentation Chapter 18 321 Table 1. Continued Name Chemical structure Purpose Patch test concentration and base Jasmine absolute Main sensitizer not yet identified Fragrance 10–5% pet. Synthetic sandalwood Main sensitizer not yet identified Fragrance 10% pet. Cinnamic alcohol Fragrance 1% pet. Musk ambrette Fragrance, incense 5% pet. Biocheck 60 Pesticide for textiles 0.2% aq. PPP-HB Textile finish 5% eth. Impurity of commercial Main sensitizers not yet identified Dye 5% eth. CI Blue 19 (Brilliant Blue) Mercury compounds Hg2+ Bactericides 0.1–0.05% aq. or pet. (not with aluminum chamber) Nickel (sulfate) Ni2+ Metal product 5% aq. or pet. Chromate (K dichromate) Cr6+ Leather, soap 0.5% aq. or pet. while the other 3 did not notice any signs of derma- tical whitener, Tinopal or CH3566 (Table 1). This was titis such as itching or erythema before the pigmen- one of numerous optical whiteners which became tation appeared [3, 4]. available at that time to make textiles “whiter than Hyperpigmentation, with or without dermatitis, white.” Patch tests with CH3566 1% pet. finally ex- was located mostly in covered areas, such as the plained the pigmentary disorder, as they showed chest, back, waist, arms, neck, and thighs. After a pa- strong positive reactions in the patients and negative tient wanted to conceal the pigmentation by wearing results in the controls. The pigmentation was persis- long sleeves and a high-neck sweater, which she tent, but the dermatitis that often preceded hyperpig- washed with a washing powder every day, the hyper- mentation was observed to disappear following the pigmentation extended from the neck and axillae to elimination of washing powders that contained all over the neck, chest, and arms. The hyperpigmen- CH3566. Fortunately, the identification of the causa- tation was brown, slate-colored, grayish-brown, red- tive chemical was made rapidly, and the widespread dish-brown, bluish-brown, etc., according to the case, usage of CH3566 was avoided in time. and often had a reticulate pattern. The histopatholo- Pigmented contact dermatitis is rare in Cauca- gy of the pigmentation showed incontinentia pig- sians but not uncommon in Mongoloids. The next menti histologica. pigmented contact dermatitis was reported by Anco- Patch tests with the standard series current at that na-Alayón et al. in Mexico [5]. Among 53 workers time gave no information as to the causative aller- handling azo dyes in a textile factory, 12 developed a gens. However, Osmundsen noticed that the patients spotted hyperpigmentation without pruritus, and 18 had used washing powders that contained a new op- suffered from hyperpigmentation to a lesser extent. 18_319_334* 05.11.2005 10:30 Uhr Seite 322 322 Hideo Nakayama This new occupational skin disorder appeared 4 months after the introduction of a new dyeing pro- cess of azo-coupling on textiles, and most of the pa- tients had contact with azo dyes on weaving ma- chines. Hyperpigmentation varied from a bizarre dark pigmentation to a streaky milder pigmentation of the neck, arms, face, and, in exceptional cases, cov- ered areas. Histopathological examination of the pigmentary disorder showed spongiosis, irregular acanthosis, edema of the dermis, pericapillary lymphocytic infil- tration, basal liquefaction degeneration, and inconti- nentia pigmenti histologica. Melanocyte prolifera- tion at the affected sites was also noted. a Patch tests showed that 24 of the 53 workers were positive to Naphthol AS 5% in water, while the other 29, as well as 10 controls, were negative to Naphthol AS. The dermatoses disappeared after the dyeing process was changed so that the workers did not di- rectly touch Naphthol AS, an azo dye coupling agent. In the early 1980s, pigmented contact dermatitis due to Naphthol AS appeared in central Japan, but this time it was not occupational. A textile factory manufacturing flannel nightwear, a traditional Japa- nese garment called yukata, economized on water for washing the products after the process of azo- coupling using Naphthol AS. This modification of production resulted in the appearance of pigmented contact dermatitis of the covered areas of skin of people