Cheryl Levin

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.

Topical Corticosteroid-Induced Adrenocortical Insufficiency

Topical corticosteroids are often prescribed for the treatment of dermatological disorders. However, systemic adrenal insufficiency may result from their overuse. Current literature detailing both laboratory and clinical findings was analyzed, in the hopes of evaluating the health-risk potential of topical corticosteroids in producing adrenal insufficiency. Risk factors identified in this report included use of high potency corticosteroids, occlusive or prolonged treatment application, and use in thin-skinned areas. Other patients at risk for development of adrenal suppression include infants and those with damaged skin barriers. Several diagnostic tests may be utilized to measure adrenal function, though each has its limitations. The most common tests include measurement of plasma total cortisol, 24-hour steroid, adrenocorticotrophin hormone stimulation and insulin tolerance.The report finds strong laboratory evidence of adrenal hypofunction. Additionally, clinical reversible adrenal insufficiency has been observed on rare occasions. Therefore, topical corticosteroids should be used with an increased awareness of the potential for systemic adrenal suppressive effects. However, since nonreversible clinical secondary adrenocortical-insufficiency disease has not been clearly documented with even class I topical corticosteroids, native adrenal supplementation in periods of stress appears unnecessary; rare exceptions cannot be excluded.

Efficacy of corticosteroids in acute experimental irritant contact dermatitis

Background/aims: Topical corticoids are used to treat irritant contact dermatitis (ICD) in humans. However, their clinical efficacy remains sub judice. This study was designed to assess the efficacy of low‐ and medium‐potency corticosteroids on irritant dermatitis.

An overview of the efficacy of topical corticosteroids in experimental human nickel contact dermatitis

We review controlled trials of corticosteroid effect in experimentally elicited acute nickel contact dermatitis in man, in the hope of clarifying optimal efficacy for clinical use. To maximize discrimination and objectivity, we focus on data with 1 well‐characterized allergen, nickel, in studies utilizing bioengineering documentation. Higher potency corticosteroids are effective (unlike in experimental irritant contact dermatitis), but optimum schedules still require definition.

Do cool water or physiologic saline compresses enhance resolution of experimentally-induced irritant contact dermatitis?

Acute irritant contact dermatitis (ICD) is frequently treated with cool water or saline compresses. While presumed effective, little quantitative evaluation documents the treatment’s benefit. This study sought to determine the efficacy of both distilled water and physiologic saline compresses on experimentally‐induced ICD. 24‐h application of both the lipophilic nonanoic acid (NAA) and the hydrophilic sodium lauryl sulfate (SLS) were used to induce irritant contact dermatitis in 9 healthy volunteers. Following irritation, compresses were applied 0.5 h 2× daily for 4 consecutive days. Transepidermal water loss (TEWL), laser Doppler flowmetry (LDF), chromametry and visual scoring were used to quantify results. Cool compresses of both water and saline significantly reduced TEWL and LDF, with no statistically significant difference between the efficacy of the saline or water compresses. Chromametry and visual scoring did not detect a significant effect with either the water or saline compresses. The results suggest an improvement with 2×‐daily application of either water or physiologic saline compresses in the treatment of acute ICD, though true clinical benefit will be elucidated through further experimentation. Certainly, the current recommendation regarding the use of cool compresses for treating ICD should not be discarded.

Corticosteroids of Clinical Value in Lipid-Soluble-Chemical-Induced Irritation in Man?

Background: Topical corticoids are used to treat irritant contact dermatitis (ICD) in man. However, their clinical efficacy remains sub judice. Objective: The effects of corticosteroids on lipid-soluble-chemical-induced ICD in man were studied. Methods: ICD was induced by 24-h patch application of nonanoic acid (NAA) onto volunteers’ forearms. Betamethasone-17-valerate, hydrocortisone and petrolatum control were applied twice daily. Visual grading, transepidermal water loss (TEWL), laser Doppler flowmetry (LDF) and chromametry quantified responses on days 1–5 and 8. Results: On day 8, with 90% NAA, a slight, yet significant improvement in TEWL was observed with betamethasone when compared to untreated control. Betamethasone also significantly decreased chromametric values on day 8 with 90% NAA when compared to hydrocortisone. Petrolatum reduced LDF values when compared to untreated control at 60% NAA on day 3. Conclusion: The results suggest a slight improvement with betamethasone and petrolatum though their benefit in typical clinical use remains unclear.

Treatment of Irritant Contact Dermatitis

Contact with external irritating agents such as dishwashing liquid, formaldehyde, or raw meat may result in irritant contact dermatitis (ICD), a localized nonimmunologic condition. ICD ensues when irritant stimuli overpower the defense and repair capacities of the skin [34, 86]. Exposure to highly potent irritants or exposure to mild irritants for an extended period of time will increase the likelihood of developing ICD. Prevention of skin irritation is the main therapeutic strategy in irritant dermatitis. The causative irritant should be avoided, in addition to other common environmental irritants such as soaps and detergents. Regular use of emollients and the use of syndets or non-soap cleansers help to maintain the skin barrier. Protective clothing such as gloves, can reduce skin contact with environmental irritants while allowing the skin to heal. It is important that protective clothing be suitable for the purpose intended: the fact that certain gloves allow permeation of irritants and allergens is often overlooked. However, prevention itself may not be sufficient to eradicate ICD. This may be because irritated skin can become hyper-reactive, and the dermatitis may flare with even minimal contact with the eliciting substances. In addition, it is not possible to identify and avoid causative irritants in all cases. Thus, additional therapies to treat ICD are essential in certain cases. Examples of such treatments in clinical practice include cool compresses, moisturizing creams, and PUVA or UV-B phototherapy [59]. In this chapter, we explore available treatments and discuss experimental evidence of their putative mechanisms and benefits.

Topical Corticosteroids in the Treatment of Irritant Dermatitis

Taken together, the risk-benefit ratio of using topical corticosteroids for the treatment of irritant dermatitis remains unclear. The risk is well established. What is uncertain is corticoids’ clinical benefit in experimental models of irritant dermatitis. Until a clear effect with topical corticosteroids is observed, other treatment options, including prevention, cool compresses, and UV therapy should also be considered (see Chap. 50 “The Treatment of Irritant Dermatitis”). However, in clinical practice, as corticosteroids remain first-line treatment of endogenous eczema, it follows that the clinician will also prescribe them for irritant dermatitis.