All posts by Nameer Al-Sudany

Fixed drug eruption

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A few hours after taking NSAID for joint pain, the patientdeveloped pruritic multiple erythematous patches with hyperpigmented centers mainly on the face and trunk.  Patch type is the most common clinical variety of FDE.

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Dermographism

 

 

dermographism

Dermogrphism
Synonyms: dermatographism, dermatographia and dermatographic urticaria.
Dermographism is an exaggerated whealing tendency when the skin is stroked and usually presents as a sharply localized edema or wheal, with a surrounding erythematous flare occurring in seconds to minutes after the skin has been stroked.
Dermographism is the most common form of physical urticaria, followed by cholinergic urticaria. It may occur with other types of urticaria including those due to cold or pressure.

Pathophysiology:
* In 25-50% of normal people firm stroking of the skin produces first a white line, then a red line, then slight swelling down the line of the stroke, and a mild red flare in the surrounding skin.
* In 2-5% of the population this response is exaggerated enough to be called dermographism.
* The exact cause of dermographism is unknown. Histamine is the main chemical released by mast cells when the skin is stroked, but other chemical mediators may also be involved.

* Associations of dermographism:
1. Drug-induced urticaria (e.g. penicillin).
2. Thyroid disease (hypothyroidism and hyperthyroidism).
3. H2 blocker famotidine (Reported).
4. Infectious diseases (scabies or a worm infestation).
5. Diabetes mellitus
6. Onset of menopause.

Clinical features
Dermographism can appear at any age but is most common in young adults.
Once a few wheals develop, subsequent scratching readily starts others in the vicinity. These swellings die away rapidly and usually clear after half to one hour.
Triggering and exacerbating factors:
1. Nervous factor: attacks of itching and subsequent weals from scratching occur at intervals and may be related to agitation and worrying situations.
2. Hot conditions, for example, after a warm bath.
3. Minor pressure from clothing, chair seats, working with various tools, clapping the hands or energetic kissing, etc., may start up the weals.
4. They may develop after exercise if it is accompanied by knocks or pressure on the skin such as in rugby, wrestling or boxing.
5. Toweling after bathing may start weal production.

Course: Dermographism may last for months or go on indefinitely. In many patients, however, it clears within a year or two, or at least the whealing is reduced to a degree which no longer causes significant symptoms.

Treatment
You should avoid triggering factors or conditions such as hot baths or showers, rough towelling down and rough clothing against the skin. Antihistamines often give good relief from symptoms. The non-sedating ones are generally preferred. The addition of an H2 antihistamine may be of benefit. Treatment may need to be continued regularly for at least several months; intermittent therapy is of less value.

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Plane wart

 

plane-wart

Plane wart

* Flat warts may result in a considerable cosmetic concern and fear of spread and contagiousness.
* May represent a therapeutic challenge and occasionally dilemma especially in children with face involvement.
* Shaving and hair epilation should be abandoned if relevant areas are involved.
* Golden rule: with any treatment modality, at least 3 months of management is considered a reasonable therapeutic trial. So no treatment should be stopped too quickly.
* Put in mind that flat warts frequently undergo spontaneous remission, so
avoid potentially scarring therapies.
* For few lesions you may consider:
1. Light cryotherapy.
2. Topical salicylic acid products (up to 20% concentration).
3. Tretinoin cream once or twice daily, in the highest concentration tolerated to produce mild erythema of the warts.
4. Tazarotene cream or gel.
5. Imiquimod 5% cream used up to once daily can be effective. If the warts fail to react initially to the imiquimod, tretinoin may be used in conjunction.
6. 5-FU cream 5%, applied twice daily, may be effective (in resistant cases).
* For refractory lesions:
1. laser therapy in very low fluences or photodynamic therapy (PDT) might be considered before electrodesiccation because of the reduced risk of scarring.
2. Immunomodulatory therapy: Ranitidine, 300 mg twice daily or Cimetidine (25–40 mg/kg).
3. Immunotherapy: using:
* Dinitrochlorobenzene (DNCB)
* Squaric acid
* Diphencyprone
* Intralesional Candida or other antigens
These can be used on limited areas of flat warts, with the hope that the immune response will clear distant warts.
4. Oral isotretinoin therapy at 30 mg/day/ 3 months might be considered when the previous topical approaches have failed.

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Dermatitis artefacta

 

dermatitis-artefacta

Dermatitis artefacta (DA) is a condition in which skin lesions are solely produced or inflicted by the patient’s own actions due to underlying psychological problem.
Synonym: (Factitial dermatitis)

What is the difference between DA and malingering?
DA is self-inflicted skin lesions with the intent to elicit sympathy, whereas malingering is self-produced lesions either to escape responsibility, or collect disability insurance (attempt to secure an insurance claim) i.e. the objective behind malingering is material gain while in DA there is an unconscious goal of gaining attention and assuming the sick patient role.

* DA is more common among females than males with a ratio of 3:1.
* It commonly occurs in teen’s age group or early adulthood.
* DA often is encountered among:
(a) Persons who are emotionally immature.
(b) Those having psychosocial or interpersonal difficulty.
(c) Persons with an attention seeking behavior.

How to expect a rash to be DA?
1. Lesions do not conform to those of known dermatoses. However, occasionally it may closely simulates a known dermatosis that it becomes very difficult to differentiate !
2. Lesions having bizarre shapes with irregular outlines in a linear or geometric pattern.
3. Lesions are usually clearly demarcated from surrounding normal skin.
4. The lesions usually present all of a sudden and do not evolve gradually without any prior signs or symptoms.
5. The lesions usually found on sites that are readily accessible to the patient’s hands e.g. face, hands, arms or legs. The lesions are rarely seen on the right hand, right wrist, or right arm, unless the patient is left-handed.
6. The patients will usually deny that the rash is self induced.
7. Often there is a “hollow” history and the patient isusually unable to detail how the lesions appeared or evolved.

Mechanism of induction: Lesions may be produced by a variety of mechanical or chemical means, including fingernails, sharp or blunt objects, lit cigarettes and application or injection of chemical irritants and caustics.

Clinically: The appearance of lesions varies depending on methods used to injure the skin. The lesions range from red patches, swelling, blisters, denuded areas, crusts, cuts, burns, gangrene and scars. At times the only sign may be the indefinitely delayed healing of an operative wound, which is purposely kept open by the patient.

Management
1. Avoid direct confrontation with the patient. Instead the doctor should create an empathetic and non-judgemental environment.
2. It is best not to reveal any suspicion of the cause to the patient and to establish the diagnosis definitively without the patient’s knowledge.
3. Consultation with an experienced psychiatrist is prudent, although this is often refused.
Prognosis: Resolution of the current underlying psychological problem will bring about a cure for the time being but dermatitis artefacta tends to wax and wane with the circumstances of the patient’s life.

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Psoriasis

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A 55-year-old woman with strong family history of psoriasis presented with many well-demarcated, red plaques covered with white silvery scales on the lower limbs and trunk. She claimed exacerbation of her lesions on psychological upsets.

 

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Rosacea

Rosacea

Rosacea is one of the difficult inflammatory dermatoses to be treated. Management of rosacea may include the following:
I. Avoid factors causing facial flushing, such as:
* Sun (use light oil-free facial sunscreens).
* Spicy or hot food.
* Hot showers, baths and warm rooms.
* Oil-based facial creams. Use water-based make-up.
II. Systemic antibiotics:
1. Tetracyclines (Doxycycline or minocycline)
2. Co-trimoxazole
3. Metronidazole.
III. Topical agents (mild-moderate cases): avoid topical corticosteroids, although they may give some improvement within first 2-3 weeks due to their antiinflammatory and vasoconstrictive effects but usually they result in exacerbation or deterioration later on..
1. Metronidazole cream or gel
2. Azelaic acid cream or lotion
3. Ivermectin cream (controlling demodex mites and as an anti-inflammatory agent).
4. Brimonidine gel is used to treat facial redness. It results in short-term vasoconstriction but has no effects on telangiectasia.
5. Calcineurin inhibitors such as tacrolimus ointment and pimecrolimus cream are reported to help some patients with rosacea.
IV. Isotretinoin (in resistant cases and may be needed in low dose for long periods). Contraindication in patients with eye involvement.
V. Clonidine (an alpha2-receptor agonist) and carvedilol (a non-selective beta blockers with some alpha-blocking activity) may reduce the vascular dilatation that results in flushing. Side effects may include low blood pressure, GI symptoms, dry eyes, blurred vision and low heart rate.
VI. Vascular laser or IPL: for persistent telangiectasia.
VII. Surgery for rhinophyma: Reshaping the nose surgically or with carbon dioxide laser.

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