AUTHOR AND EDITOR INFORMATION

Section 1 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

INTRODUCTION

Section 2 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Background

Riehl melanosis is a nonpruritic pigmentary dermatosis affecting the face. It was first observed in 1917. It is characterized by brownish grey facial pigmentation that is more marked on the temples and the forehead. Riehl melanosis was later noted to occur in people with dark complexions in whom hyperpigmentation with pigment incontinence may be the main sign of contact dermatitis caused by certain allergens. Today, Riehl melanosis is almost synonymous with pigmented contact dermatitis of the face, the most common causes of which are sensitizing chemicals in cosmetics. Histologically, an interface reaction is present with liquefaction degeneration of the basal cells. A mixed infiltrate composed of lymphocytes and histiocytes is present in the papillary dermis with melanophages and pigmentary incontinence.

This distinctive pattern of pigmentation was common in Vienna from 1916-1920. The disappearance of the disease with the end of the war seemed to relate it to factors associated with wartime living conditions, and melanosis was sometimes characterized as war dermatosis.

Many cases were seen during World War II in France, and, again, many theories were put forward. It is described as melanodermatitis toxic lichenoides by Pierini of Argentina who made the following synopsis: "a similar pigmentation which had previously been described by Hofmann and Habermann in 1917 and 1918 from the Bonn clinic. They considered the cause to be due to photo action of tar derivatives." In the period between the two World Wars, the term Riehl melanosis became widely used for facial melanosis caused by external chemical agents. However, Riehl favored etiologies other than the locally active chemical agents in describing his cases of melanosis. During World War II, a surge in cases of Riehl melanosis was observed in Europe. From 1945-1948, 165 cases were diagnosed; 162 were in women, and 3 were in men.

After World War II, many cases were seen in Japan. Asian skin has a tendency for persistent lichenoid pigmentation, but these cases mainly involve the faces (ie, the cheeks) of women. Findlay described cases in the Bantu in South Africa and named poor nutrition as a predisposing factor. Its association with cosmetic usage was recognized by 1960. Sato found positive patch test results to some of the patients' products tested. Results were difficult to evaluate because of positive results in control subjects. In 1969, a systematic study was undertaken with 477 cosmetic components to identify offending allergens. Most of these were coal tar–derived pigments, such as drugs and cosmetics (D&C) red 31 (brilliant lake red), D&C red 17, and lithoe red BA CA. Kozuka et al showed the sensitizer in D&C red 31 to be an impurity, phenyl-azo-2-naphthol (PAN). Other sensitizers were fragrance materials and, sometimes, bromides.

In the late 1960s, Osmundsen reported an outbreak of contact dermatitis in Denmark due to an optical whitener, Tinopal CH 3566. He saw 120 patients in 8 months; 7 of these patients had bizarre pigmentation, 3 of whom had no previous dermatitis. He called this pigmented contact dermatitis. In 1973, Nakayama introduced the term pigmented cosmetic contact dermatitis.

Results of the systematic testing were published in 1976, and an allergen control system evolved. Studies were also undertaken by Sugai et al who found that, in most cases, pigments were responsible and some results of the photo-patch test were positive. The number of new cases since 1978 has fallen due to allergen avoidance. Reports of sporadic outbreaks and cases continue (eg, geraniol in a face powder [Serrano, 1989], musk ambrette in incense [Hayakawa, 1987], musk ambrette in aftershave lotion [Parodi, 1987], azo dyes in a dye factory [Eyomoto]).

Pathophysiology

Although causes can be diverse, the term Riehl melanosis has been adopted to fit the typical facial pigmentation with a grey shimmer of pigmented cosmetic contact dermatitis as described by Nakayama.

The low concentrations at which fragrances are used is suggested to explain why they do not provoke spongiosis in the middle of the spinous cell layer but instead accumulate to produce type IV allergic cytolytic reactions at the epidermal basal layer. When the basement membrane is damaged by the allergic reaction, melanin from the destroyed cells is dropped into the papillary dermis to be ingested by macrophages, particularly in Asian skin. Histopathologically, this is manifested as interface dermatitis of the lichenoid type rather than a toxic reaction. Imokawa and Kawai have provided clinical evidence that allergic contact dermatitis can stimulate the epidermal pigment cell function in a very specific way. They also demonstrated a melanogenic potential for a limited number of allergens.

Frequency

United States

The incidence is not known. Most cases are reported outside of the United States, particularly from Japan.

International

No international statistics are available. This type of pigmentation was common in Vienna from 1916-1920 and was reported by Riehl in 1917. His cases were of men, women, and children. Cases have been reported in countries, such as South America, France, Japan, South Africa, and Denmark.

Race

Other than cases described during World War I and World War II, most cases have been reported from Japan and affect Asians. These are cases of pigmented contact dermatitis, which is a type of Riehl melanosis.

Sex

Pigmented contact dermatis has mainly been reported in women.

Age

Pigmented contact dermatitis is mainly a problem of young–to–middle-aged women.

CLINICAL

Section 3 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

History

Pruritus may precede the development of the pigmentary changes.

Physical

• The onset of diffuse or patchy brown pigmentation on the cheeks and the forehead is rather sudden. It is more intense on the forehead and the temples, and severe cases may look black, purple, or blue-black.
• Reticular patterning of the pigmentation is often encountered; occasionally, erythematous macules or papules are present, suggesting a mild contact dermatitis. It essentially is nonpruritic.
• UV exposure may have some part to play because of the pattern (mainly on women's cheeks) and the fact that the patch test reactions are never pigmented.

Causes

• Optical whitener: In 1970, Osmundsen reported contact allergy to the optical whitener Tinopal CH 3566. The allergy resulted in intense, bizarre hyperpigmentation in 7 patients. Skin biopsy samples revealed hydropic degeneration of the basal layer with pigmentary incontinence. Osmundsen labeled it pigmented contact dermatitis.
• Formaldehyde, brilliant lake red R, musk ambrette: Pigmented contact dermatitis resulting from formaldehyde in packing adhesive tapes, coal tar dyes (particularly, brilliant lake red R [azo dye]), and musk ambrette in incense has also been reported, mainly from Japan. More recently, Sudan I in brilliant lake red was found to be a major impurity and a potent sensitizer. These studies suggest that melanosis may be a feature of contact dermatitis.
• Aniline dyes: Pierini from Argentina reported 20 cases, all in women, with melanosis caused by aniline dye (orange II) in face powders.
• Geraniol and lemon oil
• • Serrano et al reported a 27-year-old woman from the United States with dark brown facial pigmentation and ill-defined erythematous patches resulting from the use of a compact face powder containing geraniol and lemon oil. Pigmentation cleared 6 months after use of the face powder was ceased. Geraniol (a well-known sensitizer) in the powder was thought to be the main offending agent. However, it was possible that the pigmentation could have resulted from a phototoxic reaction to the lemon oil.
  • Naganuma et al had demonstrated phototoxicity to lemon oil, which is attributable to bergapten and oxypeucedanin, but none of the lemon oils from various parts of the world was phototoxic at a concentration of 20%. This explains why the International Fragrance Association recommends a maximum content of 10% lemon oil in fragrance compounds.
  • These cases, particularly from Japan, clearly imply contact allergy to cosmetics resulting in pigmentary facial dermatosis; hence, Japanese authors have proposed the name pigmented cosmetic dermatitis. Similarities do exist between pigmented cosmetic dermatitis and pigmented contact dermatitis. Both result from exposure to small amounts of contact allergens, and eczematous lesions are not seen in either condition. However, differences occur in causative agents when race and sex are considered. In Japanese studies, fragrance compounds are implicated much more frequently.

DIFFERENTIALS

Section 4 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Other Problems to be Considered

Photoallergic reactions

Melasma is one of the main differential diagnoses. It has a typical spectacle-shaped configuration. Moreover, melasma does not show features of mild dermatitis. It is frequently associated with pregnancy, UV exposure, and contraceptive use.

Spotty dark pigmentation around the eyes may look like nevus of Ota.

Thiazide leukomelanoderma, also known as photoleukomelanodermatitis Kobori, has a reticular leukoderma with patchy hyperpigmentation, which can differentiate it from Riehl melanosis.

Lichen planus pigmentosum and actinic lichen planus can be difficult to differentiate except by patch testing and/or withdrawal of the suspected agent.

Acute or chronic inflammatory processes in the skin usually result in melanin hyperpigmentation. Progressive damage to the dermoepidermal junction results in leakage of melanin into the dermis, which results in a rather persistent, sometimes slate-grey pigmentation. This is observed, for instance, in lichen planus, lichenoid drug eruptions, lupus erythematosus, Riehl melanosis, and melanodermatitis toxica.

Hyperpigmentation may also occur in primary irritant dermatitis and allergic contact dermatitis.

WORKUP

Section 5 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Lab Studies

• Patch test
• Photo-patch test

Procedures

• Skin biopsy - Hematoxylin and eosin stain

Histologic Findings

Interface changes occur with liquefactive basal cell degeneration. A moderate lymphohistiocytic infiltrate is present in the upper dermis, mainly in a perivascular distribution. Melanophages and incontinentia pigmenti are also present in the upper dermis. Atrophy of the epidermis may be present, but spongiosis is absent. Direct immunofluorescence studies are negative, ruling out hyperpigmented lupus erythematosus. These histologic findings are similar to those of lichen planus and lupus erythematosus. Staining with periodic acid-Schiff may show a thickened basal layer, and staining with Fontana-Masson usually reveals increased melanin.

TREATMENT

Section 6 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Medical Care

• Avoidance of the allergen is necessary when it is identified.
• UV light may have a role to play; theoretically, some patients may benefit from sun avoidance and sunblocks where photoaggravation is established.
• No effective treatment/cure of Riehl melanosis has been reported.

Consultations

Referral for cosmetic camouflage may be suggested if the cosmetic disability is distressing to the patient.

MEDICATION

Section 7 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

No drug therapy is effective.

FOLLOW-UP

Section 8 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Prognosis

• Riehl melanosis tends to persist.

REFERENCES

Section 9 of 9

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

• Findlay GH. Some observations on melanosis of Riehl. S Afr Med J. 1952;26:373-5.
• Fujimoto K, Hashimoto S, Kozuka T, et al. Occupational pigmented contact dermatitis from azo-dyes. Contact Dermatitis. Jan 1985;12(1):15-7. [Medline].
• Hayakawa R, Matsunaga K, Arima Y. Airborne pigmented contact dermatitis due to musk ambrette in incense. Contact Dermatitis. Feb 1987;16(2):96-8. [Medline].
• Imokawa G, Kawai M. Differential hypermelanosis induced by allergic contact dermatitis. J Invest Dermatol. Dec 1987;89(6):540-6. [Medline].
• Kobori T, Araki, Toda K. Photoleukomelanodermatitis (Kobori) caused by benzothiazidiazine derivatives. Jap J Dermatol. 1966;76:665.
• Kozuka T, Tashiro M, Sano S, et al. Brilliant Lake Red R as a cause of pigmented contact dermatitis. Contact Dermatitis. Sep 1979;5(5):297-304. [Medline].
• Naganuma M, Hirose S, Nakayama Y, et al. A study of the phototoxicity of lemon oil. Arch Dermatol Res. 1985;278(1):31-6. [Medline].
• Nagao S, Iijima S. Light and electron microscopic study of Riehl''s melanosis. Possible mode of its pigmentary incontinence. J Cutan Pathol. 1974;1(4):165-75. [Medline].
• Nakayama H, Harada R, Toda M. Pigmented cosmetic dermatitis. Int J Dermatol. Nov 1976;15(9):673-5. [Medline].
• Nakayama H, Matsuo S, Hayakawa K, et al. Pigmented cosmetic dermatitis. Int J Dermatol. Jun 1984;23(5):299-305. [Medline].
• Osmundsen PE. Pigmented contact dermatitis. Br J Dermatol. Aug 1970;83(2):296-301. [Medline].
• Parodi G, Guarrera M, Rebora A. Lichenoid photocontact dermatitis to musk ambrette. Contact Dermatitis. Mar 1987;16(3):136-8. [Medline].
• Riehl G. Uber eine eigenartige melanose. Wien Klin Wochensschr. 1917;30:280-1.
• Rorsman H. Riehl''s melanosis. Int J Dermatol. Mar 1982;21(2):75-8. [Medline].
• Serrano G, Pujol C, Cuadra J, et al. Riehl''s melanosis: pigmented contact dermatitis caused by fragrances. J Am Acad Dermatol. Nov 1989;21(5 Pt 2):1057-60. [Medline].
• Sugai T, Takahashi Y, Takagi T. Pigmented cosmetic dermatitis and coal tar dyes. Contact Dermatitis. Oct 1977;3(5):249-56. [Medline].
• Ukei C, Oiwa K, Matasunaga K. Occupational contact dermatitis. Skin Res. 1983;23:368-76.

Article Last Updated: May 17, 2006