Ochronosis in black South Africans who used skin lighteners

Exogenous ochronosis associated with hydroquinone: a systematic review

Exogenous ochronosis is a potential side effect associated with hydroquinone, and treatment is often unsatisfactory. Our study objectives were to review data on hydroquinone-associated ochronosis to determine risk factors for patients experiencing this adverse event. On September 27, 2020 (MEDLINE/PubMed), and October 30, 2020 (Scopus and Web of Science), databases were searched for "ochronosis + hydroquinone" by both authors to reduce risk basis. PRISMA reporting guidelines were used to select 56 articles with a total of 126 patients with hydroquinone-associated ochronosis. Included articles described hydroquinone-associated ochronosis. Articles were excluded if they had irrelevant content, were non-English language text, and were non-case studies. Full text articles were assessed and recorded. Cross-tabulation analysis was performed on categorical data, and Fisher exact test was performed. Ochronosis was most often reported in middle-aged women (53.2%), of African descent (45.2%), Black races (55.5%), and Fitzpatrick skin types V-VI (52.4%). It was most frequently reported with unknown and hydroquinone concentrations greater than 4% (32.5 and 35.7% cases, respectively). Median duration of use was 5 years, with only four cases reported with courses 3 months or shorter and eight cases reported with use 1 year or less. All patients presented with facial blue-black or gray-blue macules in a reticulate, lace-like fashion. Histopathology consistently showed solar elastosis and brownish-yellow, 'banana-shaped' fibers between degenerated collagen fibers of the papillary dermis. Based on these findings, we conclude that hydroquinone in concentrations above 4% and in treatment courses longer than 3 months may be associated with new-onset ochronosis.

Exogenous Ochronosis (EO): Skin lightening cream causing rare caviar-like lesion with banana-like pigments; review of literature and histological comparison with endogenous counterpart

Ochronosis is a cutaneous disorder caused by the accumulation of phenols, either endogenously as homogentisic acid in patients with alkaptonuria (autosomal recessive disorder with deficiency of the enzyme homogentisic acid oxidase), or exogenously in patients using phenol products such as topical creams containing hydroquinone or the intramuscular application of antimalarial drugs. Exogenous ochronosis (EO) typically affects the face and was reported in patients with dark skin such as Black South Africans or Hispanics who use skin-lightening products containing hydroquinone for extended periods. Recently more cases have been reported worldwide even in patients with lighter skin tones, to include Eastern Indians, Asians, and Europeans. However, just 39 cases of EO have been reported in the US literature from 1983 to 2020. Here we present two cases; a 69 and a 45-year-old female who were seen for melasma, given hydroquinone 4% cream daily and tretinoin 0.05%. Both patients noticed brown spots on their cheeks, which progressively enlarged and darkened in color. The diagnosis of ochronosis was confirmed by characteristic histopathological features on the punch biopsy. Unfortunately, neither patient responded to multiple treatments (to include, tazarotene 0.1% gel and pimecrolimus ointment, topical corticosteroids, and avoidance of hydroquinone containing products). We also present a case of classic (endogenous) ochronosis in a patient with alkaptonuria to picture the histological similarities of these two entities. EO is an important clinical consideration because early diagnosis and treatment may offer the best outcome for this notoriously refractory clinical diagnosis.

Exogenous Ochronosis as an Elastotic Disease: A Light-Microscopic Approach

BACKGROUND

Exogenous ochronosis (EO) is a deposition disease associated with application of hydroquinone-containing preparations. Characteristic ochronotic bodies (OBs) arise from endogenous connective tissues, most often reported as collagen. We highlight a significant role for elastic fibers as a precursor tissue.

OBJECTIVE

To evaluate elastic tissue pathology in EO, specifically as it relates a precursor role in ochronotic body formation.

METHODS

In this retrospective observational study, a literature review using PubMed/MEDLINE database was conducted to ascertain the most commonly ascribed precursor connective tissue. Eleven histopathologic cases of EO were identified. Patient demographics and clinical characteristics were recorded. Slides were reviewed for the presence and grade of solar elastosis (SE), the relationship of OBs to elastotic material, the presence of elastotic fibers transitioning to OBs, and positivity of bodies with Verhoeff-van Gieson elastic tissue stain.

RESULTS

Elastic fibers are uncommonly reported as the major precursor tissue of OBs. SE was uniformly present in our cases, and the majority demonstrated heavy/high-grade elastosis. Elastotic fibers transitioning to OBs were observed in all cases, and the bodies demonstrated Verhoeff-van Gieson positivity.

LIMITATIONS

Small sample size.

CONCLUSIONS

Ochronotic body formation is associated with SE, and bodies appear to arise from damaged elastic fibers.

The Pot Calling the Kettle Black? Gender-specific Health Dimensions of Colour Prejudice in India

This paper examines the fairness industry in India, tracing its historical and cultural origins, and exposing its impact upon contemporary Indian society. The aim of this paper is two-fold. First, it shows how India's historical preoccupation with fair skin is in fact racism and sexism expressed through various cultural and historical mediums and reinforced by the contemporary beauty industry. It also highlights the risk of skin diseases such as ochronosis that are associated with the array of fairness products containing bleaching agents currently on the market. Consequently, the fairness phenomenon' in India is an important public health issue that has not to date attracted sufficient attention from academics or the medical establishment, unlike its parallel in black culture and society. The conclusion contains a list of recommendations to address the issue in a multidimensional fashion and is aimed at medical professionals, women's advocates, and those involved in the beauty and fashion industry.

Foreign Body Granulomas

A large list of foreign substances may penetrate the skin and induce a foreign body granulomatous reaction. These particles can enter the skin by voluntary reasons or be caused by accidental inclusion of external substances secondary to cutaneous trauma. In these cases, foreign body granulomas are formed around such disparate substances as starch, cactus bristles, wood splinters, suture material, pencil lead, artificial hair, or insect mouthparts. The purpose of this article is to update dermatologists, pathologists, and other physicians on the most recent etiopathogenesis, clinical presentations, systemic associations, evaluation, and evidence-based management concerning foreign body granulomatous reactions of skin.

Exogenous Ochronosis

Exogenous ochronosis (EO) is a cutaneous disorder characterized by blue-black pigmentation resulting as a complication of long-term application of skin-lightening creams containing hydroquinone but may also occur due to topical contact with phenol or resorcinol in dark-skinned individuals. It can also occur following the use of systemic antimalarials such as quinine. EO is clinically and histologically similar to its endogenous counterpart viz., alkaptonuria, which, however, exhibits systemic effects and is an inherited disorder. Dermoscopy and in vivo skin reflectance confocal microscopy are noninvasive in vivo diagnostic tools. It is very difficult to treat EO, a cosmetically disfiguring and troubling disorder with disappointing treatment options.

Cutaneous deposits

: The cutaneous deposition disorders are a group of unrelated conditions characterized by the accumulation of either endogenous or exogenous substances within the skin. These cutaneous deposits are substances that are not normal constituents of the skin and are laid down usually in the dermis, but also in the subcutis, in a variety of different circumstances. There are 5 broad categories of cutaneous deposits. The first group includes calcium salts, bone, and cartilage. The second category includes the hyaline deposits that may be seen in the dermis in several metabolic disorders, such as amyloidosis, gout, porphyria, and lipoid proteinosis. The third category includes various pigments, heavy metals, and complex drug pigments. The fourth category, cutaneous implants, includes substances that are inserted into the skin for cosmetic purposes. The fifth category includes miscellaneous substances, such as oxalate crystals and fiberglass. In this article, the authors review the clinicopathologic characteristics of cutaneous deposition diseases, classify the different types of cutaneous deposits, and identify all the histopathologic features that may assist in diagnosing the origin of a cutaneous deposit.

Effect of combination of 1064 nm Q-switched Nd:YAG and fractional carbon dioxide lasers for treating exogenous ochronosis

We describe three cases of exogenous ochronosis of the malar areas due to long-term application of skin-lightening agents for melasma, effectively treated by combination of Q-switched Nd:YAG and the fractional carbon dioxide lasers. None of these lasers has been reported to be used to effectively treat ochronosis before. The Q-switched Nd:YAG laser is capable of disintegrating dermal ochronotic fibers, thereby facilitating their phagocytosis and elimination via lymphatics. The fractional carbon dioxide laser is believed to assist transepidermal elimination of the onchronotic material. We believe successful treatment of ochronosis is possible when both mechanisms are applied.

Exogenous ochronosis - successful outcome after treatment with Q-switched Nd:YAG laser

BACKGROUND

Exogenous ochronosis (EO), a disfiguring cutaneous complication of topical hydroquinone use, is difficult to treat. There are few reports of successful outcomes following treatment with different modalities.

OBJECTIVE

We assessed the results of treatment of EO with the Q-switched Nd:YAG laser.

MATERIAL AND METHODS

Patients with histologically-confirmed EO were treated with the Q-switched Nd:YAG laser.

RESULTS AND CONCLUSION

Q-switched Nd:YAG laser treatment appears to be effective in reducing the dyschromia of EO.

Pulmonary and systemic toxicity following exposure to nickel nanoparticles

Nanoparticles are being used in ever increasing numbers in a range of industrial and medical products. Questions surrounding their potential to cause toxic effects in humans have been raised. Although animal experiments predict that nanoparticles are more toxic than their larger counterparts there are few descriptions in the literature of human exposure. A case described in 1994 has been re-examined from a pathology perspective. The subject, a 38-year-old previously healthy male, inhaled nanoparticles of nickel while spraying nickel onto bushes for turbine bearings using a metal arc process. He died 13 days after being exposed and the cause of death at autopsy was adult respiratory distress syndrome (ARDS). Nickel particles <25 nm in diameter were identified in lung macrophages using transmission electron microscopy. High levels of nickel were measured in his urine and his kidneys showed evidence of acute tubular necrosis.

Management of hyperpigmentation in darker racial ethnic groups

Dyschromias, in particular hyperpigmentation, are major issues of concern for people of color. Pigmentary disorders such as melasma and postinflammatory hyperpigmentation (PIH) can cause psychological and emotional distress and can pose a negative impact on a person's health-related quality of life. The precise etiology of these conditions is unknown. Therapies for melasma and PIH target various points during the cycle of melanin production and degradation. Therapies for these conditions include topical agents and resurfacing procedures. Hydroquinone remains the gold standard of topical agents. Other efficacious agents include kojic acid, azelaic acid, mequinol, and retinoids. Cosmeceutical agents include licorice, arbutin, soy, N-acetyl glucosamine, and niacinamide. Resurfacing procedures that have been used to treat melasma and PIH include chemical peels, microdermabrasion, lasers, and intense pulsed light. These procedures are best used in combination with topical bleaching agents. Given the propensity of darker skin to hyperpigment, resurfacing procedures should be used with care and caution. Maximal results are best achieved with repetitive, superficial, resurfacing modalities. In addition, ultraviolet protective measures such as broad-spectrum sunscreens are fundamental to the successful management of these conditions.

Cutaneous annular sarcoidosis developing on a background of exogenous ochronosis: a report of two cases and review of the literature

Exogenous (cosmetic) ochronosis is caused by the long term use of skin-lightening creams containing hydroquinone. Three cases of systemic sarcoidosis with cutaneous sarcoidal granulomas, which developed on ochronotic skin were last described by Jacyk in 1995. Dogliotti and Leibowitz previously reported cases of granulomatous ochronosis with sarcoid-like histological changes but with no associated systemic sarcoidosis. We report two additional cases of cutaneous sarcoidal granulomas, which developed on a background of cosmetic ochronosis in patients recently diagnosed with systemic sarcoidosis.

Complications of chronic use of skin lightening cosmetics

Skin lightening (bleaching) cosmetics and toiletries are widely used in most African countries. The active ingredients in these cosmetic products are hydroquinone, mercury and corticosteroids. Several additives (conconctions) are used to enhance the bleaching effect. Since these products are used for long duration, on a large body surface area, and under hot humid conditions, percutaneous absorption is enhanced. The complications of these products are very serious and are sometimes fatal. Some of these complications are exogenous ochronosis, impaired wound healing and wound dehiscence, the fish odor syndrome, nephropathy, steroid addiction syndrome, predisposition to infections, a broad spectrum of cutaneous and endocrinologic complications of corticosteroids, including suppression of hypothalamic-pituitary-adrenal axis. In this era of easy travels and migration, African patients with these complications can present to physicians anywhere in the world. It is therefore critical for every practicing physician to be aware of these complications.

The safety of hydroquinone: A dermatologist's response to the 2006 Federal Register

Recently, the US Food and Drug Administration proposed a ban on over-the-counter hydroquinone mainly on the basis of high absorption, reports of exogenous ochronosis in humans, and murine hepatic adenomas, renal adenomas, and leukemia with large doses over extended time periods. Systemic exposure to hydroquinone from routine topical application is no greater than that from quantities present in common foods. While murine hepatic adenomas increased, murine hepatocellular carcinomas decreased, suggesting a protective effect. Renal tumors are sex, species, and age specific and therefore do not appear relevant to humans after decades of widespread use. Murine leukemia has not been reproducible and would not be expected from small topical doses. Finally, a literature review of exogenous ochronosis and clinical studies employing hydroquinone (involving over 10,000 exposures under careful clinical supervision) reveal an incidence of exogenous ochronosis in the United States of 22 cases in more than 50 years. Therefore, the proposed ban appears to be unnecessarily extreme.

The safety of hydroquinone

Hydroquinone is one of the most effective molecules for the treatment of hyperpigmentary disorders, with over 40 years of efficacy and safety data. Concerns over its safety have been raised because of the fact that it is a derivative of benzene and because of the long-term side-effects observed with cosmetic products containing high concentrations of hydroquinone. However, despite 40-50 years use of hydroquinone for medical conditions, there has not been a single documented case of either a cutaneous or internal malignancy associated with this drug. This article reviews the evidence for the safety of hydroquinone in the treatment of hyperpigmentation conditions.

Exogenous and Endogenous Cutaneous Anomalies and Curiosities

Exogenous and endogenous substances can produce some interesting cutaneous abnormalities. Exogenous lesions are externally introduced materials or foreign bodies. Endogenous lesions are substances that result from tissue host response to an injury or physical insult. There may be an overlap of these endogenous and exogenous lesions such that externally introduced materials can lead to peculiar tissue reactions. Pathologists should be aware of these anomalies as many of them can simulate neoplasms (ie, Monsel's reaction, polyvinylpyrrolidone disease, silica reaction) and inflammatory (ie, paraffinoma) and infectious processes (ie, Drysol(R) reaction and Lycopodium granuloma). The most interesting and important entities within each of these categories are presented with essential clinical and pathologic descriptions.

Treatment of Exogenous Ochronosis With a Q-Switched Alexandrite (755 nm) Laser

BACKGROUND

Exogenous ochronosis is a cutaneous disorder characterized by blue-black or slate-gray hyperpigmentation resulting from the prolonged use of certain topical agents, most commonly hydroquinones. It is notoriously difficult to treat.

OBJECTIVE

To report the effectiveness of a quality-switched (QS) 755-nm alexandrite laser in treating hydroquinone-induced exogenous ochronosis.

METHODS

Hydroquinone-induced exogenous ochronosis in two patients was treated with a QS alexandrite laser. The first patient received six treatments (average fluence=7.8 J/cm(2)) at 2-month intervals. The second patient received four treatments (average fluence=6.9 J/cm(2)) at 4-month intervals. Biopsies of lesional skin were obtained before and after laser treatment for histologic evaluation.

RESULTS

Significant lightening of the pigmented skin areas was achieved in both patients without scarring or textural changes. Decreased dermal pigmentation was observed on histologic examination of treated skin specimens.

CONCLUSION

The QS alexandrite laser can effectively treat exogenous ochronosis without untoward side effects.

Exogenous ochronosis. An update on clinical features, causative agents and treatment options

Exogenous ochronosis is clinically and histologically similar to its endogenous counterpart; however, it exhibits no systemic effects and is not an inherited disorder. It is characterized by an asymptomatic hyperpigmentation of the face, sides and back of the neck, back, and extensor surfaces of the extremities. The associated ochronotic discoloration most commonly results from use of products containing hydroquinone. It also occurs following use of antimalarials and products containing resorcinol, phenol, mercury or picric acid. The etiology of hydroquinone-induced hyperpigmentation in exogenous ochronosis remains speculative. The majority of patients with this condition are Black, but it has been reported to occur in Hispanics and Caucasians. Exogenous ochronosis is prevalent among South African Blacks, but is believed relatively uncommon within the US. The reasons for this phenomenon are not clear, but it could be a result of the use of skin care products containing resorcinol in combination with hydroquinone or the use of hydroquinone in a hydroalcoholic lotion. Treatment of this condition is difficult. The offending agent must be avoided, but improvement occurs only slowly. A number of topical agents have been studied as have dermabrasion and the use of lasers. Controlled studies in larger numbers of patients are require to determine the true efficacy of newer treatments.

Papuloverrucous colloid milium: an occupational variant

We report a case of adult colloid milium in a 47-year-old mechanic with a long history of professional contact with lubricating oils and of sun exposure. In addition to the typical translucent papules seen on the forehead, there were warty papules on the backs of both hands with unusual histological and ultrastructural features: marked hyperplasia of the epidermis with orthokeratotic hyperkeratosis and papillary deposits of colloid material that were contiguous with the basal layer of the epidermis. The hand lesions caused by occupational exposure to mineral oils and solar radiation represent an occupational variant of adult colloid milium.

Exogenous ochronosis

Ochronosis is an uncommon condition characterized by yellow-brown pigment deposits in the dermis. It occurs in exogenous and endogenous forms. We report a case of exogenous ochronosis in a Hispanic woman and discuss the different forms of this condition. We treated the lesions with Q-switched ruby laser.

The combination of 2% 4-hydroxyanisole (Mequinol) and 0.01% tretinoin is effective in improving the appearance of solar lentigines and related hyperpigmented lesions in two double-blind multicenter clinical studies

BACKGROUND

Solar lentigines are a chronic condition of the aging population resulting from years of cumulative sun exposure. A topical treatment that is both safe and effective would be welcome and useful. Combinations of therapeutic agents are often used and allow synergy of mechanisms with tolerability. A tyrosinase inhibitor in use in Europe, 4-hydroxyanisole (Mequinol), and the retinoid tretinoin have been used singly as depigmenting agents.

OBJECTIVE

The efficacy and safety of the combination product of 2% 4-hydroxyanisole (4HA [mequinol]) /0.01% tretinoin solution (tradename Solagé) were evaluated in two phase III, randomized, controlled, double-blind trials.

METHODS

Subjects were randomized to treatment with 4HA/tretinoin solution, one of the active components (4HA or tretinoin), or vehicle. Subjects applied the test solution with a wand applicator twice daily to all solar lentigines and related hyperpigmented lesions on the face, forearms, and backs of hands for up to 24 weeks. Trial 1 had a 24-week no-treatment regression phase and trial 2 had a 4-week no-treatment regression phase. Information collected included clinical assessments of Target Lesion Pigmentation, Physician's Global Assessment of Improvement/Worsening, an Assessment of Overall Cosmetic Effect, and a Subject's Self-Assessment Questionnaire.

RESULTS

The 4HA/tretinoin combination was clinically superior to each of its active components and to the vehicle in the treatment of solar lentigines. At the end of treatment, in trial 1 and trial 2, 4HA/tretinoin was statistically superior to each of its active components and vehicle on the forearms and face (P </=.03), except versus tretinoin on the face in trial 2 (P =.2). In trial 2, a trend toward greater efficacy of 4HA/tretinoin over tretinoin on the face was demonstrated at the end of treatment (P =.2), which was also increasingly evident at the end of the 4-week follow-up (P =.06). Most skin-related adverse events were mild and were similar for both the 4HA/tretinoin and tretinoin treatment groups.

CONCLUSION

For the treatment of solar lentigines and related hyperpigmented lesions, the topical combination product containing 2% 4HA/0.01% tretinoin solution is well tolerated and superior to either active component.

The toxicology of hydroquinone--relevance to occupational and environmental exposure

Hydroquinone (HQ) is a high-volume commodity chemical used as a reducing agent, antioxidant, polymerization inhibitor, and chemical intermediate. It is also used in over-the-counter (OTC) drugs as an ingredient in skin lighteners and is a natural ingredient in many plant-derived products, including vegetables, fruits, grains, coffee, tea, beer, and wine. While there are few reports of adverse health effects associated with the production and use of HQ, a great deal of research has been conducted with HQ because it is a metabolite of benzene. Physicochemical differences between HQ and benzene play a significant role in altering the pharmacokinetics of directly administered when compared with benzene-derived HQ. HQ is only weakly positive in in vivo chromosomal assays when expected human exposure routes are used. Chromosomal effects are increased significantly when parenteral or in vitro assays are used. In cancer bioassays, HQ has reproducibly produced renal adenomas in male F344 rats. The mechanism of tumorigenesis is unclear but probably involves a species-, strain-, and sex-specific interaction between renal tubule toxicity and an interaction with the chronic progressive nephropathy that is characteristic of aged male rats. Mouse liver tumors (adenomas) and mononuclear cell leukemia (female F344 rat) have also been reported following HQ exposure, but their significance is uncertain. Various tumor initiation/promotion assays with HQ have shown generally negative results. Epidemiological studies with HQ have demonstrated lower death rates and reduced cancer rates in production workers when compared with both general and employed referent populations. Parenteral administration of HQ is associated with changes in several hematopoietic and immunologic endpoints. This toxicity is more severe when combined with parenteral administration of phenol. It is likely that oxidation of HQ within the bone marrow compartment to the semiquinone or p-benzoquinone (BQ), followed by covalent macromolecular binding, is critical to these effects. Bone marrow and hematologic effects are generally not characteristic of HQ exposures in animal studies employing routes of exposure other than parenteral. Myelotoxicity is also not associated with human exposure to HQ. These differences are likely due to significant route-dependent toxicokinetic factors. Fetotoxicity (growth retardation) accompanies repeated administration of HQ at maternally toxic dose levels in animal studies. HQ exposure has not been associated with other reproductive and developmental effects using current USEPA test guidelines. The skin pigment lightening properties of HQ appear to be due to inhibition of melanocyte tyrosinase. Adverse effects associated with OTC use of HQ in FDA-regulated products have been limited to a small number of cases of exogenous ochronosis, although higher incidences of this syndrome have been reported with inappropriate use of unregulated OTC products containing higher HQ concentrations. The most serious human health effect related to HQ is pigmentation of the eye and, in a small number of cases, permanent corneal damage. This effect has been observed in HQ production workers, but the relative contributions of HQ and BQ to this process have not been delineated. Corneal pigmentation and damage has not been reported at current exposure levels of <2 mg/m3. Current work with HQ is being focused on tissue-specific HQ-glutathione metabolites. These metabolites appear to play a critical role in the renal effects observed in F344 rats following HQ exposure and may also be responsible for bone marrow toxicity seen after parenteral exposure to HQ or benzene-derived HQ.

Chlamydia pneumoniae in atheroma: consideration of criteria for causality

AIMS

(1) To seek evidence of the existence of Chlamydia pneumoniae in a spectrum of atheromatous lesions in different types of arteries from individuals of different ages, using a polymerase chain reaction (PCR) assay supported by electron microscopy and immunocytochemistry; (2) to use electron microscopy to examine interactions between C pneumoniae and the cells present in the arterial tissue; (3) to assess the extent to which the data fulfil the criteria for causality.

METHODS

At necropsy examination, 35 arterial specimens were taken from 25 subjects. The grade of atheroma was determined macroscopically and microscopically and the tissues coded and examined by the three techniques.

RESULTS

Of the 35 specimens, 24 had macroscopic or microscopic atheromatous lesions of varying degree. Twenty two of the 35 specimens were examined by electron microscopy, C pneumoniae-like bodies being found in 11 (50%); seven specimens were examined by the immunocytochemical method, positive staining being detected in three; and all specimens were examined by the PCR technique, 15 (43%) being PCR positive. Overall, of the 24 specimens with lesions, 17 (71%) were positive by at least one of the three tests, whereas of the 11 specimens without lesions, only one was positive. The positive specimens comprised 10 of 19 aortas, three of six iliac arteries, and one coronary and one pulmonary artery. C pneumoniae was detected in four of six specimens in which there were early changes and in a 20 year old subject. Concerning the 25 subjects, of 17 who had atheromatous arteries, 14 (82%) were C pneumoniae positive and of the eight who had normal arteries, none was positive.

CONCLUSIONS

There is a strong correlation between C pneumoniae and arterial atheromatous lesions. The organism may contribute to the disease process by damaging smooth muscle cells.

Lethal epidermolysis bullosa in black South African neonates

BACKGROUND

While there have been a number of reports of epidermolysis bullosa (EB) occurring in South African black neonates, the disorder occurs rarely and the electron-microscopic findings in affected South African patients have not been documented previously.

METHODS

All patients with neonatal EB who were biopsied for electron microscopy at the South African Institute for Medical Research between 1986 and 1992 were included in the study. The eight boys and three girls had extensive blistering and all died within the first few months of life.

RESULTS

Nine of the patients showed the features of junctional EB, whereas the remaining two were classified as dystrophic EB. There were no differences in the clinical manifestations between the two categories.

CONCLUSIONS

The lethal form of EB in South African black neonates is associated with at least two types of basement membrane defect.

Hydroquinone-induced localized exogenous ochronosis treated with dermabrasion and CO2 laser

Exogenous localized ochronosis can result from the repeated use of hydroquinone-containing creams, many of which are available over the counter. We report a case that was managed by dermabrasion and CO2 laser. The incidence and proposed etiologies of hydroquinone-induced exogenous ochronosis are reviewed.

Red or rufous albinism in southern Africa

Red or rufous albinism is a rare type of oculocutaneous albinism described, but not as yet fully investigated, in Africa and New Guinea. Twelve rufous albino subjects from 10 families participated in this preliminary study. The prevalence of rufous albinism was found to be approximately one in 8,580 among school children in the negroid population. The combination of the unusual red skin colour, ginger to reddish hair colour, low susceptibility to sun damage, and minimal visual problems, in affected individuals, suggested that they form a group which is distinct from the brown and other types of albinism. The mode of inheritance was found to be recessive. Tyrosinase assays showed that rufous albinos are tyrosinase positive and on electron microscopy studies normal melanosomes and melanocytes were observed in hair bulbs and skin. Visual evoked potential testing did not show the gross decussation abnormalities of the optic pathway detected in other types of albinism. Rufous albinism might be at one end of the spectrum of types of oculocutaneous albinism and, because affected people have such mild symptoms, their inclusion in this group might be debatable.

Actinic granuloma-like change in exogenous ochronosis: case report

Exogenous ochronosis is caused by the longterm application of skin-lightening creams containing hydroquinone. This irreversible disfiguring cosmetic problem assumes epidemic proportions in South African blacks. Mild ochronosis is characterized clinically by coarsening and darkening of the skin and severe ochronosis by coalescing, caviar-like black papules and atrophy. Histology shows ochronotic collagen fibres with eventual formation of ochronotic colloid milium. A variable cellular infiltrate, which may be granulomatous, is present. We describe a 39-year-old black woman with severe exogenous ochronosis who developed superimposed annular lesions with granulomatous histology bearing great resemblance to lesions of actinic granuloma.

Demyelinisation in the spinal cord of vitamin B12 deficient fruit bats

1. Vitamin B12 deficiency induced in the fruit bat by a combination of dietary deprivation and exposure to nitrous oxide (N2O) is accompanied by profound neurological impairment, thus providing an experimental model for the study of vitamin B12 neuropathy. 2. Electron microscopy of the spinal cord of vitamin B12 deficient bats shows marked changes in the myelin of the posterior columns in the form of distension, separation and vacuolation of myelin lamellae similar to the changes described in the dietary induced B12 deficient monkey model. 3. No equivalent change occurred in bats exposed to N2O and supplemented with vitamin B12.

The fate of intravenously injected tissue ferritin in pregnant guinea-pigs

The organ distribution of intravenously injected hepatic ferritin either labelled with 59Fe or with 59Fe and 125I, was studied in pregnant guinea-pigs. At 5 h 71.2% of injected 59Fe was present in the placenta and fetus. Transfer of 59Fe to the fetus was slow, with 11.2% present at 5 h and 38.6% at 21 h. Analysis of a placental cellular lysate for 59Fe and 125I revealed that the injected iron was present as intact ferritin at 2 h but by 21 h the ferritin had been catabolized, the 125I excreted and the 59Fe incorporated into endogenous ferritin. Most of the fetal 59Fe counts were detected in the liver, with 35.3% of the transferred 59Fe in ferritin, 30.4% in haemoglobin and 10.6% in a low molecular weight pool. The uptake of labelled ferritin by the placenta was inhibited by a 300-fold molar excess of unlabelled ferritin but not by albumin, asialofetuin or by the injection of carbon particles. A nonsignificant reduction in uptake was noted after injection of mannosylated bovine serum albumin. The mannosidase inhibitor swainsonine had no effect. Iron transfer to the fetus was not affected by various microtubular inhibitors. Presaturation of endogenous transferrin with oral carbonyl iron prevented iron release from the feto-placental unit back into the maternal circulation. In consequence, marrow 59Fe uptake by the maternal marrow was reduced. The ferrous chelator 2,2'-bipyridine significantly reduced 59Fe transfer to the fetus and this occurred irrespective of whether the chelator was given prior to or after 59Fe ferritin administration. The ferric chelator desferrioxamine had no such effect. Electron microscopy of placental tissues revealed endocytosis of ferritin molecules. These results indicate that the guinea-pig placenta takes up homologous tissue ferritin and transfers the iron slowly to the fetus after reductive mobilization. The process is compatible with a receptor-mediated pathway.

Probable coexisting exogenous ochronosis and mercurial pigmentation managed by dermabrasion

A patient with blue-gray discoloration of the face is described. Her history revealed that she had used bleaching creams containing mercury and hydroquinone for many years. Biopsy specimens of the hyperpigmented areas showed deposits that were compatible with both mercury deposition and the diagnosis of exogenous ochronosis. Dermabrasion was successfully employed to remove these deposits.

Exogenous ochronosis in the United States

Two middle-aged black women reported hyperpigmentation of the face after using bleaching creams containing hydroquinone. Both noted initial lightening of facial pigmentation followed by progressive darkening of the areas to which the cream was applied. After biopsy, they were found to have exogenous ochronosis. These are the fifth and sixth cases of exogenous ochronosis reported in the United States. In this article we review the literature and discuss the possible pathogenesis of exogenous ochronosis.

Squamous cell carcinoma with anemone cell features

A tumor from a 52-year-old Albino male had the ultrastructural features of an anemone cell tumor. Evidence of squamous differentiation was seen by electron microscopy and immunohistochemistry. "Anemone cell" tumors have been shown to be classifiable as either carcinomas or lymphomas; the term therefore does not describe a discrete entity or constitute a definitive diagnosis. Treatment with radiotherapy was successful in this case, while chemotherapy appeared to have little effect.