Idiomas:
The SCENIHR opinion states:
Lamps used close to the skin could cause problems for people who are extremely light-sensitive
Source: Simon Cataudo3.5.2. Effects of fluorescence light vs. normal incandescent light on photosensitive skin related conditions
The photodermatoses are a group of skin conditions induced by light which include the Idiopathic (of unknown mechanism) photodermatoses, drug/chemical induced conditions, the genophotodermatoses. Fluorescent light has been identified as a risk factor (Rihner and McGrath 1992, Sayre et al. 2004). This section also mentions those disorders that are aggravated by sunlight.
3.5.2.1. Idiopathic photodermatoses
Although idiopathic, this group of conditions are believed to have an immunological basis.
This condition, which is the commonest of all the photodermatoses presents in spring or early summer as a pruritic erythematous papular rash on sunlight exposed sites. The skin eruption usually develops within half to a few hours of sunlight exposure. The condition usually remits over the winter months. The prevalence increases with the distance from the Equator (5% in Australia; 21% in Sweden; 15% in England)(Pao et al, 1994) and also with altitude (Dang et al. 2006). The overall European estimate is 10-20% (Stratigos et al. 2002, Bock et al. 2005, Hönigsmann 2008). Age of onset is variable with 60% arising in the first three decades, with a two to three fold higherprevalence among females (Bock et al. 2005). Polymorphic light eruption is thought to be a delayed hypersensitivity response to cutaneous neo-antigens induced in susceptible individuals by UVA and UVB sunlight containing exposure. It may be provoked by exposure to high output artificial sources.
Conclusion:
It is possible that in the most severely affected, CFL could produce the eruption [Evidence level C].
Most of the patients have a long history of recurrent contact allergy to defined allergens with features of dermatitis on photoexposed sites. Some have semi-translucent nodules termed actinic reticuloid. It occurs mainly in males over the age of 50 years with a prevalence in Scotland of 16.5:100,000 population (Dawe 2008). The skin is abnormally sensitive to UVB/UVA and frequently also visible radiation. A new type of chronic actinic dermatitis (also uncommon), associated with atopic dermatitis, has been identified in patients in their teens and 20s. Photosensitivity can be severe and broad extending from UVB to the visible region.
Conclusion:
Degree of photosensitivity suggests there may be a problem with CFL (Moseley 2008) [Evidence level C].
This is an uncommon condition that particularly affects American Indians and less frequently Caucasian and Asian populations. Age of onset is usually before 10 years and it predominantly affects females. Patients complain of a perennial problem with deterioration during spring and summer. Pruritic, patchy, oedematous erythema with papules is evident following exposure to sunlight. Repetitive UVA provocation testing usually induces lesions. Management of actinic prurigo is more difficult than that of polymorphic light eruption. Its prevalence is estimated at 3.3 per 100,000 of the general population (Dawe 2008).
Conclusion:
Severe cases may potentially be at risk from CFL (Moseley 2008) [Evidence level C].
This is an uncommon photosensitive skin disorder that affects both males and females. It may arise in any age group but is particularly common in the first four decades of life. The condition is persistent and about one-third of patients show no response to treatment. Its wavelength dependency is most commonly in the UVA region extending into the visible and occasionally also affecting the UVB region. The prevalence has been estimated to be 3.1 per 100,000 (Beattie 2003). Provocation of the lesions is relatively easy in the most sensitive group.
Conclusion:
It is possible that some patients could be at risk from CFL. It should be noted that incandescent light sources also cause problems in some patients [Evidence level C].
3.5.2.2. Drug/chemical induced photosensitivity
Many drugs are recognised as capable of inducing photosensitivity. They do so by a variety of mechanisms, commonly phototoxicity, which means that any individual exposed to a sufficient quantity of a drug and appropriate irradiation will be affected. Other mechanisms of action result in only a small number of individuals being affected. Some photosensitising drugs are listed below (Ferguson 2002). Much less common is the mechanism of drug-induced photoallergy which involves a sensitised immune system.
Phototoxicity
Amiodarone
Amiodarone is a cardiac antidysrhythmic agent that causes a burning, prickling sensation with erythema in approximately 50% of individuals on high dose. The wavelengths responsible are UVA and visible light. Unsightly slate-grey skin pigmentation may also develop.
Phenothiazine
Phenothiazine-derivative drugs have an antipsychotic action, thought to act by blocking dopaminergic transmission within the brain. They produce skin discomfort, erythema and blistering elicited by exposure to UVA. Unsightly skin discolouration may also occur.
Fluoroquinolone Antibiotics
This is a large group of drugs that exhibit variable degrees of phototoxicity. Symptoms include erythema and blistering; wavelengths responsible are mainly UVA.
Conclusion:
Given the degree of photosensitivity, it is not anticipated that drug induced photosensitivity to the above will be a particular problem when patients are exposed to CFL vs. incandescent sources [Evidence level C].
Photofrin and other Anti-cancer Agents
Photofrin and Foscan are potent intentional visible wavelength dependent photosensitisers used in photodynamic therapy of internal cancers. Photodynamic therapy can elicit skin phototoxic responses when exposed to visible light (Hettiaratchy et al, 2000).
Conclusion:
Photosensitivity might be expected to arise with CFL to a greater extent than that seen currently with incandescent light sources because of the greater amount of blue light. However, these patients are closely managed because of their known temporary phototoxicity, and so in practice this is not likely to constitute a significant problem [Evidence level C].
Psoralen Phototoxicity from Plants and Diet
Phytophotodermatitis is a group of conditions which appear following psoralen skin contact from plants along with UVA wavelength exposure. This is unlikely to be a significant problem with CFL. Psoralens are also present in foodstuffs.
Conclusion:
The amount of psoralen in the diet (celery, parsnip, limes, etc.,) when combined with fluorescent lighting is unlikely to be either an acute or chronic problem [Evidence level D].
Photo-allergic contact dermatitis
Photo-allergic contact dermatitis is an uncommon delayed-type hypersensitivity reaction elicited by low doses of UV radiation in susceptible individuals. The main groups of photocontact allergens current in the environment are sunscreen chemicals, and topical non-steroidal anti-inflammatory drugs. When the diagnosis is made, patients can quickly avoid the provoking wavelengths, usually in the UVA region.
Conclusion:
CFL are unlikely to be a significant inducing factor in this group of patients [Evidence level D].
3.5.2.3. Genophotodermatoses
This group of inherited photosensitive skin diseases include Xeroderma Pigmentosum, Cockayne’s, Bloom’s and Rothmund-Thomson Syndrome, which are quite rare. Xeroderma pigmentosum is reported as occurring in 1 of 250,000 in Europe and the USA (Robbins et al. 1974) while the other disorders are even rarer. The best understood of these is xeroderma pigmentosum. In its classical excision repair defective form, there is a marked photosensitivity to UVB wavelengths. Childhood development of skin cancer makes photoprotection against these wavelengths a priority.
Conclusion:
It is possible that unfiltered CFL could be associated with increased disease activity. Patients are currently advised to avoid unfiltered fluorescent lighting. There could be assumed to be a similar problem with other members of the group [Evidence level C].
3.5.2.4. Porphyrias
This group of mixed inherited and environmentally induced photosensitivity skin diseases relates to an accumulation of a photosensitive porphyrin within the skin. Examples of these diseases include erythropoietic protoporphyria, the main feature of which is burning or prickling pain in the skin exposed to sunlight. A few minutes of intense visible light are usually enough to elicit symptoms causing the individual to try to escape from the light source and seek relief, for example, using cold water compresses. Erythropoietic protoporphyria develops in childhood, or even during infancy. It should be noted that cutaneous porphyrias are particularly sensitive to the blue light region so there would be a theoretical argument when comparing tungsten bulbs (which have less blue light). Porphyrias are rare disorders. For example, the prevalence of congenital erythropoietic porphyria (Günther’s disease) in the UK is approximately 2 per 3,000,000 live births. Erythropoietic protoporphyria prevalence has been reported at around 1 to 2 per 100,000 inhabitants (Burns 2004, Marco et al. 2007).
Conclusion:
CFL in extremely sensitive patients could possibly produce a slight increase in the problem compared to tungsten light sources, although there is published evidence against this (Chingwell et al, 2008, in press) [Evidence level C].
Porphyria Cutanea Tarda
The prevalence of porphyria cutanea tarda is estimated to be 1:5,000. It is caused by excessive alcohol intake, chronic hepatitis infection and other factors. It produces blisters, skin fragility and hypertrichosis. It is mainly produced by visible wavelengths rather than ultraviolet A.
3.5.2.5. Photo-aggravated Dermatoses
Ten percent of patients with atopic dermatitis are aware of exacerbations triggered by sunlight. This may be due to infrared exposure and perspiration, but in other patients this does not seem to be the case.
Conclusion:
It seems unlikely that CFL would contribute significantly to this problem and might even be preferred to incandescent light sources [Evidence level D].
3.5.2.6. Lupus Erythematosus
Lupus erythematosus is a chronic autoimmune disease that is often exacerbated by sunlight exposure. Its prevalence is estimated at 27.7 per 100,000 of the general population with a much higher prevalence reported for females of Afro-Caribbean ethnicity (Hopkinson et al. 1993, Johnson et al. 1995). Some patients do describe artificial light causing problems. Provoking wavelengths seem to be predominantly in the UVB extending into UVA2. A range of skin presentations include butterfly rash, a polymorphic light eruption presentation and lupus erythematosus tumidus are examples.
Conclusion:
Through their UV component, chronic exposure to CFL could possibly be a problem. Systemic lupus is an important condition in that skin flares can be associated with internal disease activity [Evidence level C].
3.5.2.7. Skin Cancer
Ultraviolet radiation is a major environmental risk factor for skin cancers. Hence, UV radiation from artificial illumination sources should be reduced to a minimum. The UVC and UVB radiations are especially effective in damaging DNA, and in causing gene mutations and cancerous transformation of cells. Although the carcinogenic UV dose from fluorescent lighting in offices is minor (~ 1%) when compared to equal exposure times in the summer sun, old risk assessments showed that actual annual exposures of office workers could increase by 10 to 30% from the fluorescent lighting, which over a lifetime was estimated to increase the risk of squamous cell carcinomas by around 4 % with a baseline risk much lower than that for outdoor workers who dominate incidences (Lytle et al 1992). Some recent measurements (see section 3.4) showed that some commercially available CFL emit short wavelength UV radiation down to the UVC (254 nm) which is unnecessary and undesirable, and leaves room for improved lamp engineering. The most effective wavelengths in causing or stimulating skin melanoma – the most aggressive skin cancer – are not known, but UVA and longer wavelengths may be relatively more important than for skin carcinomas. It should be noted that UVA exposure from fluorescent lamps for indoor illumination is still far lower than from the sun (or artificial tanning lamps). A case-control study in a population with low sun exposure showed that melanoma risk was not associated with fluorescent lighting in the home or offices (Swerdlow et al 1988).
Conclusion:
Fluorescent lamps do not contribute significantly to the melanoma risk [evidence level A] and by analogy CFL will not [Evidence level B]. Fluorescent lamps, including CFL, are estimated to contribute insignificantly to UV doses effective in causing skin carcinomas [Evidence level B].
3.5.2.8. Conclusions regarding skin diseases
Although good quality clinical data associating fluorescent light induction (and by inference CFL) of these photosensitive diseases, is lacking, there are some experimental data supporting the belief that exposure to CFL (particularly when the source is close to the skin) may induce problems in those patients with severe photosensitivity in the ultraviolet B/A spectrum namely, xeroderma pigmentosum, and other genophotodermatoses as well as the idiopathic photodermatoses (chronic actinic dermatitis, severe solar urticaria, polymorphic light eruption and actinic prurigo). It is also possible that in cutaneous systemic lupus erythematosus problems could be induced by the UV mercury vapour lines emitted by unfiltered CFL.
It is also feasible that in some skin conditions particularly sensitive to blue light, e.g., photodynamic therapy administered patients, there could be a marginally greater reaction with CFL than seen with incandescent light sources. It does seem that these adverse reactions will occur in a relatively small number of patients and could, to a degree, be avoided by UV filtering of CFL.
Peer reviewed definitive test data comparing incandescent vs. CFL in these diseases is required to provide a clear answer to the question being asked in this report.
- There is sufficient evidence to show that UV and in some cases visible radiation from lamps can provoke a clinically significant skin reaction in light-sensitive patients [Evidence level A].
- Fluorescent lamps, including CFL emit UV radiation that may be harmful to a sub- set of particularly sensitive patients [Evidence level C].
- CFL may be harmful when in close proximity to the skin (around 20 cm or less) [Evidence level B].
Source & ©:
3. Scientific Rationale, Section 3.5. Potential mechanisms
for impact on users, Subsection 3.5.2. Effects of fluorescence light
vs. normal incandescent light on photosensitive skin related
conditions, p. 23
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