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国外疑难皮肤病病案研习八例

Case 1

"An itchy foot rash" Case preparation: Dr C Kearney Images: Dr C Meehan

History

A two year old girl presents with a 3 week history of a solitary, intensely itchy, serpiginous lesion over her left foot. This has progressed steadily in a linear direction. There are no lesions elsewhere and she is otherwise well, with no significant past medical history. She has recently been playing in a newly-fertilised garden. No one else has similar problems.

Answer: Pompholyx（汗疱疹）? No.

This pattern of eczema, affecting the hands and/or feet, is characterised by vesicles over the palmoplantar surfaces and along the lateral aspects of the digits.

Answer: Tinea pedis（脚癣）? No.

Tinea pedis may have a serpiginous, scaly edge, however this would be expected to expand radially, rather than linearly.

Answer: Scabies（疥疮）? No.

Scabetic burrows commonly occur over the feet of infants with scabies, but are typically much smaller and would be also be present in others sites.

Answer: Cutaneous larva migrans (皮肤幼虫移行症)? Yes.

This is also known as creeping eruption; sandworm eruption; plumber's itch; duck-hunter's itch.

It is caused by hookworms of various animals, of which the dog hookworm is the commonest. Specific species include Ankylostoma brasiliense, A. caninum, A. ceylonicum, Uncinaria stenocephala and Bubostomum phleboto. Adult hookworms live in the intestines of dogs and cats, and their ova are deposited in the animals' faeces. Under favourable conditions of humidity and temperature, the ova hatch into infective larvae, which will penetrate human skin. Sandy, warm, moist, shaded areas are particularly favourable, they can then lie quiet for weeks or months, or immediately begin creeping activity with the production of a wandering thread-like line, about 3mm wide, which is exceedingly itchy. The larvae advance at a rate of a few millimetres to a few centimetres daily, and are somewhat in front of the head of the track.

The disease is self-limiting, usually over a matter of weeks, although variable. Treatment options include topical thiabendazole (used in this case), oral ivermectin (a single dose of 200mcg/kg or 12 mg) or albendazole (400mg/day for 5 to 7 days), and cryotherapy.

Case 2

"An odd rash on the hip" Case preparation: Dr A Mar Images: Dr C Meehan

History

An 18-month-old boy presented with a rash over the right hip. His mother reported that the eruption began as a papule some 2 weeks previously, following what appeared to be an insect bite, and extended rapidly despite a 5-day course of erythromycin. The child was not systemically unwell but the affected skin was tender. There was no family history nor past history of atopy.

Answer: Tinea（癣）? No.

Tinea is characterised by a more slowly expanding eruption which typically has central clearing and is not tender.

Answer: Infected eczema?（感染性湿疹）No.

The annular appearance, and tenderness rather than itch, in the absence of pre-existing eczema, makes this diagnosis unlikely.

Answer: Linear IgA disease （线状IgA皮病，previously called Chronic Bullous Disease of Childhood)? No.

Although this rare condition typically occurs on the lower trunk and thighs of young children, it is characterised by tense blisters at the periphery of red plaques (so-called "string of pearls")

Answer: Bullous impetigo（大疱性脓疱疮）? Yes.

This infection is caused exclusively by toxin-producing Staph. aureus, unlike non-bullous impetigo, which may also be caused by streptococci. Although it may occur in any age group, it is more commonly reported in children. Flaccid blisters form which may rupture to leave a fine peripheral scale. Rapid extension and central clearing may give rise to annular lesions, as illustrated. Lesions may be tender, but children are generally well. Involvement of oral mucous membranes or regional lymphadenopathy are uncommon.

The organism can be isolated from a swab and often from blister fluid as well. In this case staph aureus was cultured and found to be resistant to erythromycin and penicillin but sensitive to flucloxacillin.Staph. aureus resistence to erythromycin is increasingly common.

Management included oral dicloxacillin, tap water bathing to remove loose crusts (which are infective), topical mupirocin and temporary isolation of the child from other children.Testing for and treatment of Staph. aureus nasal carriage in the patient and family members would be appropriate in recurrent cases.

Case 3

A stubborn facial rash" Case preparation: Dr C Meehan Images: Dr C Meehan

History

This 9 year old girl has a 2 month history of a facial rash. She also has mild flexural eczema but no known allergies. The rash is only mildly itchy but has spread and possibly become more inflamed since applying hydrocortisone 1% cream for 4 weeks and subsequently Kenacomb cream for 3 weeks. She is otherwise well and enjoys gardening, playing with her guinea pig, and applying nail polish and makeup.

Answer: Atopic eczema（特应性皮炎）? No

The history and features are typical of another condition.

Answer: Contact Dermatitis（接触性皮炎）? No

The history and features are typical of another condition. Note, however, that contact reactions to nail polish typically affect the face and throat rather than the fingers. Note also that allergic reactions to topical steroids or to cream preservatives are possible and should be considered if a rash is worsening. Kenacomb cream contains neomycin and ethylenediamine, both of which are potent sensitizers.

Answer: Pityriasis alba（白色糠疹）？No

This is characterized more by hypopigmentation with little or no obvious inflammation.

Answer: Perioral dermatitis（口周皮炎）?No.

This may produce a somewhat similar picture of extension despite (or, rather, due to) potent topical steroids, but would be more acneiform and less well circumscribed.

Note, however, that potent topical steroids should not be applied to facial rashes, particularly around the eyes, nose or mouth.

Answer: Tinea（癣）Yes

Examination reveals a circumscribed rash with a definite margin, and the history of extension and lack of response to (or aggravation by) topical steroids are also typical of tinea facei. A topical antifungal agent, eg an imidazole such as clotrimazole, would be appropriate. The likely source is her guinea pig, which must be treated if infected, although kittens are another common source. Pet-to-human transmission is much more likely than human-to-human spread in this example. Examination of the scalp and and rest of the body is mandatory to check for tinea elsewhere.

Notes:

a) Topical steroids can confuse the clinical features of tinea.

b) The constituents of Kenacomb have no activity against dermatophyte fungi.

c) Oral therapy is indicated for tinea capitis (scalp hair) or unguum (nails), and may be indicated for extensive or refractory skin infection.

Practice Points

1. If an eczema-like rash does not respond to topical steroids, consider the possibilty of tinea. Similarly, if a tinea-like rash fails to respond to topical antifungals, consider the possibilty of eczema.

2. If the response to a mild topical steroid is unsatisfactory, resist the temptation to just prescribe a more potent one, particularly for facial rashes. Fungal studies or a biopsy might be more appropriate.

3. Contact dermatitis due to nail varnish produces rashes over the face or thoat rather than on the fingers.

4. Contact reactions to topical steroids, to their vehicles, and/or to other contained chemicals are possible, and neomycin, which has no activity against dermatophytes, is a potent sensitizer

Case 4

An acute and extensive rash" Case preparation: Dr A Mar Images: Dr C Meehan

History

A 50 year old woman presented with a 6 week history of a rash which appeared first over her scalp and face before extending widely over the trunk and limbs. There was an orange-red, mildly scaling rash, confluent over much of the skin but with islands of sparing. In other areas there were follicular papules, and thickening of the palmar and plantar skin was noted. She complained of feeling cold and shivering and had a tachycardia, but was normotensive and afebrile. There was no history of previous rashes or medical illness. She had taken no medication.

Answer: Psoriasis（银屑病）? No.

Erythrodermic psoriasis must be considered, however the pattern of extension of the rash, its orange-red hue, and "islands" of normal skin suggest another diagnosis.

Answer: Drug reaction（药疹）?No.

There is no history of medication use and drug reactions are rarely scaly or associated with thickened palms or soles, although extensive reactions may resolve with desquamation.

Answer: Viral exanthem（病毒疹）？No.

There was no history of a prodromal illness, and while viral rashes may extend in a cephalocaudal manner, the clinical features suggest another diagnosis.

Answer: Pityriasis rubra pilaris（毛发红糠疹）? Yes.

This uncommon condition occurs most frequently in middle-aged adults and the cause is unknown. Like psoriasis, there is excessive proliferation of epidermal cells. Cephalo-caudal spread, perifollicular accentuation and yellowish, thickened palms and soles are typical. The rash often has an orange hue and scaling is mild. Islands of unaffected skin are typical and help distinguish it from psoriasis. The nails are often thickened but not pitted. Spontaneous resolution occurs within 1-3 years in 80% of cases.

Case 5.

"A streaky rash on the arms" Case preparation: Dr A Mar Images: Dr C Meehan

History

A 55 year old widow noticed two tranverse linear streaks over her left elbow, 2 months ago, after scratching the limb on a bush. She subsequently developed similar lesions over both forearms. The eruption is not itchy and she denies scratching. There are no rashes elsewhere, she takes no medication, and there are no known allergies.

Answer: Plant contact dermatitis（植物接触性皮炎）? No.

The distribution and morphology indicates another diagnosis.

Note, however, that 'streaky' rashes, generally vesicular or bullous, over exposed sites are typical of contact dermatitis due to brushing against plants.

Answer: Lichen Planus（扁平苔藓）? No.

The distribution and morphology indicates another diagnosis.

Note, however, that lichen planus is one of several dermatoses which may arise in traumatized skin, eg scratches, to produce linear rashes. This is the Koebner phenomenon.

Answer: Dermatitis Artefacta（人工皮炎）? Yes.

This is artefactual skin disease caused by patients who are aware of their actions but who, due to an underlying psychiatric disorder, deny reponsibility for their skin condition. The diagnosis should be suspected in the presence of bizarre, sharply angulated lesions or linear ulcers, usually in the setting of a vague history (so-called "hollow history"). Sites which are easily reached by the patient, such as face, arms or legs, are typically involved.

Managment: Psychiatric assessment? Yes.

In many cases dermatitis artefacta is associated with depression or an anxiety state. In chronic cases a personality disorder is often found. However, patients often resist advice to seek psychiatric care.

Practice Points:

1. Streaky, vesicular or bullous rashes over exposed skin surfaces are characteristic of contact dermatitis caused by brushing against a plant. This can be confirmed by open patch testing to suspected plants and/or by formal patch testing.

2. Dermatitis artefacta is characterized by bizarre skin lesions, generally accompanied by a vague history, denial of self-induced trauma, and by an apparent lack of concern about the eruption.

3. Several skin disorders, including lichen planus and psoriasis, may develope along cuts or scratches, resulting in linear lesions. This is the Koebner phenomenon.

Case 6

"A keratosis on the nose" Case preparation: Dr D Gill Images: Dr C Meehan

History

A middle-aged man presented with a scaly spot on his nose. This proved to be a solar keratosis and was treated with liquid nitrogen. However, general examination revealed a lesion over his lower back. He had been aware of it for several years and had not noticed any obvious change of appearance.

Answer: Seborrhoeic Keratosis（脂溢性角化病）? No.

However these may sometimes be difficult to differentiate on clinical grounds

Answer: Dysplastic Naevus（异常发育的痣）? No.

The features are those of another condition.

Answer: Haemangioma（血管瘤）?No.

The features are those of another condition.

Answer: Congenital Naevus（先天性痣）?No.

The features are those of another condition and the history does not indicate that the lesion was congenital (ie. present at birth).

Answer: Malignant Melanoma（恶性黑素瘤）? Yes.

This is a malignant melanoma, Level V, 3.5mm thick. The case is presented to demonstrate the importance of total skin examination, especially for patients presenting with sun-damaged skin or possible skin cancer. If assessment is limited to the presenting lesion, an opportunity may be missed to find other, potentially fatal tumours, particularly over the back, where self-examination is difficult.

Note: The "ABCD" rule is a useful clinical aid to help identify "suspicious" lesions. A: asymmetry; B: irregular border; C: irregular colours; D: diameter >1cm.

Note: While both histological thickness and level of invasion are routinely reported, the thickness, rather than the level of tumour is the most reliable prognostic indicator.

Management:Answer: Sentinel Node biopsy? Yes.

This technique aims to identify the closest lymph node draining the tumour site, so that it can be examined for evidence of metastatic tumour. Tumour negative sentinel nodes indicate a good prognosis, however the outlook for patients with metastases remains poor, given the current lack of adjunctive treatments of proven value.

Case 7

A tumour on a finger" Case preparation: Dr C Kearney Images: Dr C Meehan

History

A 70 year old man presents with a 6 week history of an enlarging lesion over the pad of his left ring finger. It had failed to respond to 2 treatments with cryotherapy by his local doctor, and bled vigourously after minor trauma but was otherwise asymptomatic.

Answer: Amelanotic melanoma（无黑色素性恶性黑素瘤）? No.

An important differential to consider, as amelanotic melanomas are often missed diagnoses, however, the history and features are typical of another condition

Answer: Squamous cell carcinoma（鳞状细胞癌） No.

A diagnosis worthy of consideration but there is another diagnosis that fits this clinical picture more closely. The volar aspect of the fingers would be an unusual site for SCC.

Answer: Keratoacanthoma（角化棘皮瘤）? No.

A diagnosis worthy of consideration but there is another diagnosis that fits this clinical picture more closely. The history of rapid growth is consistent with keratoacanthoma, however, the volar aspect of the fingers would be a somewhat unusual site and the features are typical of another condition.

Answer: Pyogenic granuloma（化脓性肉芽肿）? Yes.

This benign vascular lesion is also known as granuloma telangiectaticum. It is a vascular nodule that develops rapidly, not uncommonly at the site of a recent injury, and is composed of proliferating capillaries in a loose stroma. It is a common lesion affecting both sexes and occurring at any age. It is seen quite often in children and young adults, but is unusual in the elderly. The size commonly varies between 5 and 10mm, but at times it may reach 50mm. Common sites are the hands, especially over the fingers, the feet, lips, head and upper trunk, and the mucosal surfaces of the mouth and perianal area. The initial evolution is rapid and after a few weeks the growth ceases. Spontaneous disappearance rarely occurs. There is no pain, and the patients mainly complain of the appearance or of recurrent bleeding.

The pedunculated lesions are easy to treat by curettage and cauterization or diathermy coagulation of the base but a considerable proportion of granulomas recur after such treatment. Wherever possible, it is desirable to excise a narrow, but deep, ellipse of skin beneath the lesion and close the wound with sutures.

Case 8

"Rash from a cargo container?" Case preparation: Dr D Gill Images: Dr C Meehan

History

A 40 year old Customs Officer with a 3 week history of an extensive, itchy rash which developed acutely, a few days after he had been working in a shipping container. He is otherwise well, with no systemic symptoms, and while his work involves overseas travel there is no relevant medical history. He had taken no oral medication and there was no history of prior contact with anybody with infectious disease.

Answer: Guttate Psoriasis(点滴状银屑病)? No.

Look closely at the photos: there are scaly spots but also superficial ulcers, which would not be expected with psoriasis.

Note: Guttate psoriasis, which may follow a throat infection in predisposed people, displays a relatively uniform eruption of scaly spots

Answer: Pityriasis rosea（玫瑰糠疹）? No.

However this may have a similar appearance initially.

Note: Pityriasis rosea is characterized by a preceding 'herald patch'; larger lesions over the trunk, proximal limbs and throat; peripheral collarettes of scale; and a 'fir tree' distribution over the trunk.

Answer: Secondary syphilis（二期梅毒）? No.

However some variants may look similar.

Note: Secondary syphilitic eruptions are generally monomorphous and typically involve the palms, soles, oral/genital mucosa, scalp and face.

Note: However syphilis is 'The Great Mimicker', and varicelliform secondary syphilis may produce an eruption somewhat similar to this case.

Answer: Varicella（水痘）? No.

This must be considered, particularly in children, however there are no 'viral vesicles' and no systemic symptoms.

Note: Varicella appears first over the face and scalp, spreading to the trunk but with relative sparing of the extremeties, and is accompanied by systemic symptoms.

Note: Varicella features a polymorphous eruption of lesions in all stages of developement, ranging from macules to papules, superficial thin-walled vesicles, pustules, crusts and post inflammatory marks.

Answer: Kaposis sarcoma, HIV-AIDS（卡波西肉瘤）? No.

The morphology and history is typical of another condition.

Answer: Pityriasis lichenoides（斑丘疹性红皮病）? Yes.

This is pityriasis lichenoides et varioliformis acuta (PLEVA), an uncommon eruption which may manifest at the acute (PLEVA) or chronic (Pityriasis Lichenoides Chronica: PLC) ends of a spectrum, or with intermediate/combined features as are seen here. The cause is unknown but may be an immunologic reaction to an infectious agent, with histology showing 'lymphocytic vasculitis' and some cases demonstrating clonal T cell populations. There is a rare, ulceronecrotic, hyperacute variant (PLUH) but the prognosis is generally good, and while some consider lymphomatoid papulosis, a rare condition with malignant histology, to be at the far end of the spectrum, others regard this is a distinct condition with a different course, histology and prognosis.

PLEVA affects mainly the trunk and limbs, with sparing of the face, scalp, palms and soles. Lesions may be seen in all stages of developement, from papules to central vesiculation or necrosis, crusted erosions, or ulcers healing with varioliform scars.

PLC is characterized by successive crops of red-brown papules with an overlying, loosely adherent, mica-like scale. These lesions may occur with PLEVA lesions. The course is variable, with some cases resolving within a few months but others relapsing or merging into the chronic form and persisting for many months or years.

Treatments include phototherapy, oral tetracycline or erythromycin, and for severe, acute disease, oral steroids and/or methotrexate.

Management

1. Measures to control the hyperhidrosis and to minimise occlusion by footwear are most important. In this instance, he must remove his work boots whenever possible.Occlusion by the boots and sweating will leave the soles moist or even wet for prolonged periods, providing optimum conditions for the bacteria to grow.

2. Antiperspirants will help, as will oral (erythromycin) or topical antimicrobials (eg, erythromycin, fusidic acid, clotrimazole), however the mainstay of treatment is control of the sweating.

3. Topical steroids are not indicated

Practice Points

1. Guttate psoriasis, which may follow a throat infection in predisposed people, displays a relatively uniform eruption of scaly spots.

2. Pityriasis rosea is characterized by a preceding 'herald patch'; larger lesions over the trunk, proximal limbs and throat; peripheral collarettes of scale; and a 'fir tree' distribution over the trunk.

3. Secondary syphilitic eruptions are generally monomorphous and typically involve the palms, soles, oral/genital mucosa, scalp and face. However syphilis may mimic a wide variety of skin conditions, so the possibility must always be kept in mind.

4. Varicella appears first over the face and scalp, spreading to the trunk but with relative sparing of the extremeties, and is accompanied by systemic symptoms. It features a polymorphous eruption of lesions in all stages of developement, ranging from macules to papules, superficial thin-walled vesicles, pustules, crusts and post inflammatory marks.