Medical Unit - Treatment guidelines for contact dermatitis

Contact dermatitis is a common problem among workers and constitutes approximately 5.7 million physician visits per year. All age groups are affected, and there is a slight female predominance as reflected in patients seen for diagnostic patch testing.

The complex nature of the chemical environment (natural and synthetic) in which we live brings the skin into contact with many potential exposures which may or may not pose a hazard, depending on individual susceptibility.

There are more than 100,000 chemicals in the environment today. Almost any substance can be an irritant, depending on the exposure circumstances. Further, over 2,800 substances have been alleged to be contact allergens. The potential for these substances to cause contact dermatitis varies greatly, and thus the severity of the dermatitis ranges from a mild, short-lived condition to a severe, persistent, job-threatening and sometimes life-threatening disease.

Contact dermatitis is an altered state of skin reactivity induced by exposure to an external agent. Substances which produce this condition after single or multiple exposures may be irritant or allergic in nature and will often present as an inflammatory process. Direct tissue damage results from contact with irritants. Following contact with strong irritants the reaction is immediate with blistering and pain, resembling a burn. From contact with weak irritants, the reaction develops more slowly, over several days or weeks, with redness, pain and/or itching, and scaling. Tissue damage by allergic substances, however, is mediated through immunologic mechanisms; the reaction consists of redness, marked itching, slight thickening of the skin and/or small vesicles at the site(s) of contact. The generic term for both of these conditions is contact dermatitis. Tissue damage by allergic substances is mediated through immunologic mechanisms. The most common clinical expression of this induced inflammation is dermatitis (eczema).

CAUTION: Exogenous dermatoses may morphologically and histologically mimic endogenous dermatoses, and vice versa, and may co-exist. Before considering a job change, or if chronicity is involved (more than 12 weeks), appropriate consultation is indicated.

Scope of the guidelines: This guideline deals with the assessment and treatment of contact dermatitis in working-age adults. Another contact elicited phenomenon, the contact urticaria syndrome, which in its immunologic form, has produced fatalities, is not discussed here.

A physician may vary from these rules if in the judgment of the physician, variance is warranted to meet the health care needs of the patient and that variance remains within the standards of practice generally accepted by the health care community, and the physician documents the need for the variance in the evaluation report or the medical treatment record in the manner that is generally accepted by the health care community.

Not every medical situation can be addressed in these regulations and medical standards change constantly. The documentation required of the physician is necessary to monitor and explain the use of variances.

I. Initial assessment

A. Purpose

Accurate diagnosis is the key to proper management of contact dermatitis. If the agent(s) causing the dermatitis can be found and successfully avoided, recovery can be anticipated; but if contact continues, the dermatitis may become chronic, disabling, and a serious threat to continued work and the activities of daily living. After prolonged and repeated episodes of dermatitis, a small number of individuals may not fully recover, even with adequate medical care and following avoidance of its causes.

B. Appropriate assessment methods

1. History may include:
a. General medical status
b. Onset

1) Location
2) Symptoms -- itching, burning, sting
3) Description -- redness, blisters, scales, urtication (welts), dryness, rash
4) Home remedies used, including over-the-counter preparations.

c. Progression

1) Relation between exposure and time interval of dermatitis
2) Relation to home and recreation
3) Relation to specific work activity
4) Relation to activity -- sweating, friction, pressure, heat, cold, etc.
5) Relation to sun/air exposure, season, and time of day

d. Remissions

1) Relation to non-work related weekends and/or vacations
2) Response to treatment and rapidity of recurrence after discontinuing medication
3) Relation to stress and/or anxiety
4) Relation to water exposure

e. Occupational history

1) Exact nature of work
2) Duration of present activity
3) Others similarly affected
4) Changes in procedure or chemical exposure
5) Protective measures -- type and effectiveness
6) Related symptomatology -- burning eyes, sneezing, wheezing, asthma, and anaphylaxis
7) Cleansing agents -- type and frequency of use
8) Hand washing frequency and agents used; protective creams--type and use
9) Second job
10) Review of Material Safety Data Sheets in relation to patient's job
11) Moisturizers and over the counter topical
12) Other factors

f. Other exposure

1) Hobbies and non-work activities

a) Gardening, house plants, lawn care, and other outdoor activities (e.g., poison ivy, oak, and sumac, chrysanthemums, primula, Peruvian lily)
b) Knitting, sewing, macrame
c) Painting, ceramics, jewelry
d) Cooking, baking
e) Wood working, carpentry, gluing
f) Auto, motorcycle, truck repair
g) Photography and photographic developing
h) Sports
i) Other

2) Animals and substances on their skin or fur

a) Dogs and cats
b) Birds and caged animals
c) Farm animals, horses
d) Other

3) Cosmetics, fragrances, and personal care products

a) Soaps and detergents
b) Shampoos and other scalp/hair products
c) Creams and lotions
d) Perfumes, colognes, deodorants
e) Nail polishes, artificial nails, and nail/cuticle products
f) Consort or other interpersonal contact/products
g) Other

4) Household activities and products

a) Dishwashing products
b) Laundry detergents
c) Furniture waxes, polishes, and dusting agents
d) Bathroom cleaning agents
e) Floor care products
f) Use of gloves (type and frequency)
g) Other

g. Family history

1) Atopic background -- nature, prevalence and severity including relation to eczema
2) Ichthyosis, psoriasis, and hand eczema or other significant skin disorder
3) Family members with contact dermatitis

a) Relationship
b) Age of onset
c) Type and severity of problems
d) Results of therapy and/or testing procedures
e) Other

h. Past medical history

1) History of contact dermatitis -- nature, severity, and causativeagent(s), if known
2) Previous treatment

a) At onset
b) Self treatment -- over the counter treatments -- relation to dermatitis
c) By other physicians

3) Medications -- topical and systemic -- past and present -- relation to dermatitis as well as medication allergy
4) Other

2. Physical examination may include:

a. Location

1) Symmetry
2) Involved vs. uninvolved skin

a) Demarcation-sharp or unclear
b) Evidence of protection by clothing
c) Distribution suggestive of photo or air-borne pattern exposure (e.g., exposed or uncovered skin areas)

b. Lesion type

1) Acute

a) Dermatitis (eczema)
b) Vesicular/bullous
c) Urticarial
d) Excoriations
e) Crusts

2) Chronic

a) Lichenification
b) Pigmentary changes
c) Atrophy
d) Scarring
e) Loss of hair

c. Other

3. The patch test

The patch test is the standardized diagnostic procedure of choice
for allergic contact dermatitis. In general, practitioners who do
such patch testing should adhere to the following guidelines when
performing patch tests. It should be used only by primary care
physicians with previous knowledge, training and skill in the
application and interpretation of such testing. In the vast majority
of cases, patients who require patch testing should be referred to
a dermatologist or allergist who includes patch testing in
his/her practice.

a. Standardized test kits containing a number of allergens are
available. In testing with substances brought from work,
appropriate dilutions must be used to avoid irritant reactions
which can be very severe. In general, testing with raw
substances from the workplace should be done by
a dermatologist or allergist experienced in patch testing.

b. The most widely used patch test material consists of strips
of paper tape onto which are fixed 8 mm diameter aluminum
discs. A small amount of allergen is placed within these discs,
discs, covering slightly more than one-half the diameter of the
disc providing a dose approximately 17 ul.

c. Apply the patch to the upper or mid back, which must be free
of dermatitis and devoid of hair. If shaving is necessary, it
should be done only with an electric razor.

d. Leave the patch in place and keep dry for two days (48 hours)
before removing unless symptoms of severe reaction occur.

e. Read tests:

1) The same day that patches are removed from the skin, allowing 20-30 minutes for erythema to resolve before preliminary interpretation.
2) One additional reading at 72 or 96 hours, and
occasionally at one week. Reading solely at 48 hours
will miss up to 35 percent of positive reactions.
3) If two readings are impossible, a single reading three or four days (72-96 hours) after patches are initially applied.

f. Grade test reactions according to intensity (International Contact Dermatitis Research Group Scale): (Color plates available)

1) 0 = no reaction
2) ?(+ or - reaction) = weak erythema only
3) 1+ = erythema with edema
4) 2+ = erythema and papules (tiny vesicles are present over the surface).
5) 3+ = vesicles or bullae

g. Interpret reactions cautiously:

1) 0 = no evidence of contact allergy.
2) ? = doubtful existence of contact allergy.
3) 1+ = possible contact allergy. (1+ is a common intensity of false positive reactions).
4) 2+ and 3+ = probably contact allergy.
5) If several questionable and 1+ reactions are present along with strong 2+ or 3+ reactions,
the weaker reactions may mean that the "excited skin syndrome" is present, the weak reaction
representing only irritation.

4. Additional tests of occasional value

a. Skin biopsy to differentiate from other diseases

b. Open application of a suspected allergenic product to the antecubital fossa twice daily for up to one week (the PUT, Provocative Use Test or ROAT, repeat open application test). This is applicable to leave-on products intended for use on the skin, not wash-off products.

c. Prick or scratch test in the evaluation of contact urticaria. Emergency resuscitation equipment should be available. Contact urticaria should first be evaluated with an open test on sites adjacent to active dermatitis.

d. Chemical analysis of environmental materials to determine if they contain a substance to which the patient is patch-test positive. The most commonly employed of these is the dimethylglyoxime test for nickel.

e. Potassium hydroxide (KOH) preparation, fungal and bacterial cultures and appropriate laboratory examinations as needed.

C. Inappropriate initial assessment methods

1. Occlusive patch test with irritant concentrations of material or material where the irritant concentration is unknown

2. A specific IgE (RAST) test is not helpful in the diagnosis of contact dermatitis (with the exception of contact urticaria when prick or scratch tests may be hazardous).

3. Sublingual allergen application with vital sign monitoring as an indicator of adverse reactions.

D. Evolving diagnostic tests

In vitro lymphocyte stimulation tests, migration inhibition factor, and other laboratory tests of lymphokine production remain investigational tools which at present are insufficiently standardized to allow clinical application.

II. Initial treatment

A. Purpose

The purpose of initial treatment is to prevent further exposure to the causative agent(s) and control itching and/or edema.

B. Appropriate initial treatment methods

1. Topical treatment

Topical treatment alone may be indicated for mild cases of contact dermatitis, limited site of involvement, acute contact dermatitis when the offending agent has been removed, or chronic contact dermatitis with limited symptoms.

Topical therapy most commonly used includes but is not limited to:

a. Cool compresses with saline, water, milk, aluminum subacetate, or other agents for acute, blistering dermatitis
b. Shake lotions, such as calamine
c. Topical corticosteroid cream, ointment, lotion, gel, or spray
d. Colloidal oatmeal baths
e. Antibiotic treatment, if required, should be systemic only (Many antibiotic creams and ointments are sensitizing.)
f. Coal tar in low concentration (in chronic eruptions)
g. Emollients, lubricants, moisturizers (in chronic eruptions) and for prevention of irritation
h. Non-alkaline cleansers instead of soap.

2. Systemic treatment

Systemic treatment may be indicated for control of itching and/or edema even in cases of limited extent. Systemic treatment may also be indicated for moderate to severe acute and/or chronic contact dermatitis.

Systemic therapy most commonly used includes but is not limited to:

a. Antihistamine -- sedative types for nighttime sedation; non-sedating types for daytime use.
b. Corticosteroids, oral or intramuscular (Intravenous corticosteroids may be useful in severe acute cases)
c. Antibiotics, oral or parenteral (when secondary infection may be
d. Other anti-inflammatory or immunologic agents.

3. Other

a. Ultraviolet B radiation (used only for chronic, resistant dermatitis, with treatment supervised by a dermatologist)
b. Psoralen (topical or oral) and ultraviolet A radiation, supervised only by a dermatologist
c. Mechanical protection against allergens and irritants (e.g., gloves, protective clothing, protective barrier creams)
d. Removal or avoidance of causal allergens and/or irritants

4. Education

Patient education about the nature of the dermatitis, triggering allergen or irritant factors, and suggestions for avoidance or substitution of these factors in the patient's environment may be helpful in management. Discussion should include proper selection and wearing of gloves and other protective clothing, personal cleanliness, use of hand creams, avoidance of home irritants, especially soaps, shampoos, solvents, etc.

III. Secondary assessment (reassessment at one to three months)

A. Purpose

It is critical to obtain specialized consultation and possibly a complete diagnostic patch testing and possibly immediate type testing before considering a worker as being unfit for work for dermatologic reasons. For a simple case of irritant contact dermatitis, if there is no improvement after two to three weeks of treatment, and especially if the condition is becoming worse, referral to a dermatologist should be made. Referral should be made immediately, however, if there is uncertainty regarding the diagnosis.

B. Appropriate secondary assessment methods

In unclear diagnoses, other lab tests including KOH preparation, microbial cultures, and biopsy should be considered.

IV. Secondary treatment

A. Purpose

In unusual cases, specialized nonspecific therapies may be helpful. Consultation should be sought before initiating this.

B. Appropriate secondary treatment methods

This includes localized or systemic PUVA (Psoralen UVA).

V. Prevention

A. Purpose

Minimizing exposure to allergens is essential.

B. Appropriate preventive measures

1. Appropriate engineering steps to enclose the chemical and/or physical exposure
2. Appropriate hygiene including:

a. Change of clothing
b. Protective clothing
c. Appropriate gloves.

3. Appropriate dermatotoxicologic consultation to identify an alternative process or chemical to substitute for the agent causing a documented allergic contact dermatitis.
4. Appropriate skin care with the least irritating and sensitizing cleansing agents and moisturizers

VI. Primary references

Adams, R.M., M.D., Occupational Skin Disease, 2nd Ed., W.B. Saunders,
Philadelphia, 1990.

Cronin , E., FRCP, Contact Dermatitis, Churchill Livingstone, New York, 1980.

Office of Disease Prevention and Health Promotion, U.S. Public Health Service, Disease Prevention/Health Promotion: The Facts, Bull Publishing Co., Palo Alto 1988.

Fisher, A.A., Contact Dermatitis, 3rd Ed., Lea & Febiger, Philadelphia, 1986.

Foussereau, J., Benezra, C., Maibach, H. Occupational Contact Dermatitis: Clinical and Chemical Aspects, 1982, Munskgaard, Copenhagen and W.B. Saunders Co., Philadelphia, 1982.

Funk, J.O., Maibach, H.I., Horizons in Pharmacologic Intervention in Allergic Contact Dermatitis, Journal American Academy of Dermatology, 1994; 31(No. 6):999-1014.

Larsen, W.G., Adams, R.A., Maibach, H.I., Color Text of Contact Dermatitis. W.B. Saunders Co., Philadelphia, 1992.

Menne, T., M.D., Maibach, H.I., M.D., Exogenous Dermatoses: Environmental Dermatitis, CRC Press, Inc., Boca Raton, Fl. 1990.

Maibach, H.I., Occupational and Industrial Dermatology, 2nd Ed., Year Book Medical Publishers, Inc., Chicago, 1987.

Marzulli, F.N., Maibach, H.I., Dermatotoxicology 4th Ed., Hemisphere Publishing Corp. New York, 1991.

Melmstrom, G, Wahlberg, H, Maibach, H.I., Protective Gloves for Occupational Use, CRC Press, Boca Raton, FL, 1994. (ISBN 0-8493-7359-X)

Menne, T, Maibach, H.I, Hand Eczema, CRC Press, Boca Raton, FL, 1994. (ISBN 0-8493-7355-7)

Rycroft, R.J.G., Menne, T., Frosch, P.J., Benezra, C., Textbook of Contact Dermatitis. Springer, New York, 1992.