Saturday, 5 November 2011





12-year old patient presented with this type of scaling [scales, large “plate-like” , very thick, dark brown and firmly adherent, have been over most of the skin surface including the face (A and B) and accentuated on lower extremities (C)] which started within the first month of life. Which congenital disorder of cornification is this?

Normally, cornification involves the construction of the cornified envelope from intracellular protein precursors including loricrin and involucrin. These are cross-linked to lipid ceramides in the granular layer by the action of transglutaminase 1. Kinetic studies in this disease revealed a near-normal transit time, and it is therefore classified as a retention disorder of cornification (retention hyperkeratosis with hypergranulosis). Mutations in the keratinocyte transglutaminase-1 gene on chromosome 14q11.1 interfere with the crosslinkage of loricrin and involucrin and the formation of the cornified cell envelope (retention hyperkeratosis). What are the other congenital disorders of cornification that show retention hyperkeratosis?

Short and long answers are provided below as comments. 

Thursday, 3 November 2011



The history is characteristic. This 22-year old patient with a common fungal infection was satisfied initially with the cream prescribed by another doctor. He stopped applying the cream, the eruption relapsed. Further applications brought renewed relief and the cycles were repeated. He developed few persistent nodules, which become insuppressible by the cream. Scaling was lost in the groins areas as shown (A), and bruise-like brownish discolouration was seen (A). Scaling (arrows) was still seen on the buttocks (B). From which site autoinfection can occur?

Two other patients with the same history and similar findings. 

Spread to the scrotum is common, but scaling is minimal and inflammation is inconspicuous against a background erythema. The penis is occasionally affected as shown above. 

An extension of infection from the groins to the buttocks is not uncommon as shown above.

Short and long answers are provided below as comments.

Monday, 31 October 2011

Electrosurgical waveforms

Electrosurgery (diathermy) equipment converts domestic alternating current into high-frequency alternating current (of various types) which is converted to heat energy as it passes THROUGH a high-resistance medium such as the skin. Haemostasis can only be achieved satisfactorily if the area being diathermied is relatively dry. Each type of electrosurgical current produces its own wavy pattern of current flow, called the waveform.

Different electrical waveforms produce tissue desiccation/fulguration, coagulation, or cutting. Some machines are designed to produce all effects. There is however some overlap between these effects so that the desiccation waveform (dehydration) can be used, albeit not perfectly, for coagulation and cutting.

Monoterminal procedures (without a dispersive plate) produce desiccation/fulguration. Biterminal procedures produce coagulation with a dispersive plate or bipolar electrode (bipolar forceps, keeps the current flow on the surface travelling from one tine of the forceps to the other) or produce coagulation with cutting or pure cutting without appreciable coagulation effect (electrosection) with a dispersive plate. Pure cutting is useful in diagnostic biopsy avoiding the tissue damage associated with coagulation (after the biopsy is taken, haemostasis can be attained by switching to coagulation). 

In electrofulguration, the needle tip is not in contact with the skin. As the spark jumps between the skin and the needle its energy is spread over a greater area, resulting in more superficial tissue damage (superficial dehydration). Deep penetration does not occur because the charring acts as an insulating barrier.

Thursday, 27 October 2011


What does the development of an exophytic nodule on this naevus in the child patient, that has been present since birth, usually represent? Does the patched-hedgehog signalling pathway malfunction in this regard? What advice would you give the parent?

In this naevus, around puberty there is enlargement of the 
sebaceous glands, which are often located abnormally high in the 
dermis, with an increased number of closely set lobules and 
malformed ducts (A). A variety of appendageal tumours, sometimes
multiple, may develop within sebaceous naevi. The most commonly 
reported are trichoblastoma and syringocystadenoma papilliferum
(B). It should be noted that basaloid proliferations (arrow
that are seen in as many as half of all cases of naevus sebaceous
are not always easily differentiated from basal cell carcinoma
(BCC). Misinterpretation of trichoblastoma and basaloid
 proliferation as BCC has caused problems in the past.

How to differentiate between BCC and trichoblastoma 

Short and long answers are provided below as comments.

Tuesday, 25 October 2011


Non-Langerhans cell histiocytosis represents a broad group of different disorders characterized by the proliferation of histiocytes other than Langerhans cells. One of which, is multicentric reticulohistiocytosis shown here in this middle-aged woman with yellow-pink papules and nodules (with scleral involvement). Multicentric reticulohistiocytosis has subtype (multiple reticulohistiocytomas) that is restricted to skin. It is possible that the diffuse, purely cutaneous form is an early stage of multicentric reticulohistiocytosis before the appearance of joint and other lesions. In multicentric reticulohistiocytosis the onset of arthropathy, may precede, follow, or accompany the onset of skin lesions. No treatment is of consistent value for this disease.

The characteristic pathological picture in multicentric reticulohistiocytosis is of infiltration by mononucleated and multinucleated giant cells with voluminous eosinophilic ground-glass cytoplasm (finely granular). In early lesions, the predominant infiltrating cells are histiocytes, lymphocytes and eosinophils, with few giant cells, but the giant cell infiltrate quickly follows.
The multinucleate giant cells (the hallmark of the disease) have 3-10 or more nuclei, which may be placed haphazardly, or along the periphery, or clustered in the centre of the giant cell. They contain variable amounts of lipid and free or esterified cholesterol.

Severe involvement of the face may lead to a leonine facies. Does this disease show Köbner (Koebner) response? What are the diseases that may lead to a leonine facies?

Sunday, 23 October 2011



This young adult presented with these scaly lesions (A). On Wood’s light examination (B), these lesions showed yellow fluorescence, and unsuspected similar lesions more widely scattered were revealed as well. What is the fluorescent substance? Is it water-soluble?

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This page was last updated in
June 2014

Thursday, 20 October 2011

Cryotherapy of a cherry angioma

Cherry angiomas (Campbell de Morgan spots) occur predominantly on the trunk and proximal parts of the limbs. Cryotherapy option, when treatment is required, works but it is a less-well controlled method than others.  

The freeze time BEGINS at the moment the target area of skin is COMPLETELY frozen (the ice ball). Liquid nitrogen is then sprayed intermittently on the target area to maintain the ice ball at the required margin. Liquid nitrogen spray is halted when the freeze time is up.

In cherry angiomas: Freeze time --> 10 seconds, lesions in general often need more than one freeze. Margin of normal skin also frozen (mm): 1

In larger lesions, the liquid nitrogen spray is directed from the side of the lesion
. This allows the extraneous liquid nitrogen to ricochet from the surface of the lesion into the air rather than over normal surrounding skin. If the larger lesion is sprayed directly from the top the extraneous liquid nitrogen will travel across the normal surrounding skin and invariably the physician will terminate cryosurgery before the central base of the lesion has been sufficiently frozen. 

The extent of injury is determined by the rate of freezing, the coldest temperature reached, the freeze time and the rate of thawing. Pain peaks during thawing. Use words like discomfort, burn, or pain whenever appropriate when describing the reaction so that the patient will know what to expect.

Sunday, 28 August 2011

Erythema dyschromicum perstans treatment options

Erythema dyschromicum perstans (EDP) has similarities to lichen planus pigmentosus although the precise relationship of the two conditions has yet to be established.

How to treat it?

There is no established therapy for this condition. Having said so, there are 5 options to be considered.

1)     No therapy. The condition is persistent, but may resolve over time. In a series of 4 patients followed up for 2 years in Finland, 3 showed spontaneous resolution.

2)     Vitamin A. Lichen planus pigmentosus has responded (50 – 100% clearance in some patients)  to vitamin A prescribed in pulses of 100,000 units daily for 15 days (pulses were repeated  up to 10 times) in a study. This recommendation is considered by those who reckon that EDP is the same entity as lichen planus pigmentosus.

3)     Dapsone 100 mg/day for 8 to 12 weeks might be effective (anecdotal report).

4)     Oral steroids might work (anecdotal report).

5)     Clofazimine* 100 mg/day for 12 weeks. It seems that clofazimine reduces the inflammatory response in EDP. 4 out of 6 patients showed marked improvement.

*Barabda L, Torres-Alvarez B, Cortes-Franco R et al. Involvement of cell adhesion and activation molecules in the pathogenesis of erythema dyschromicum perstans (ashy dermatosis): the effect of clofazimine therapy. Arch Dermatol 1997; 133: 325–9.

Friday, 1 July 2011

Situations to remember (1)

Transsexualism and schizophrenia 

I recall seeing a young man who presented with secondary transsexualism of relatively short duration. Later, frank schizophrenia developed and it seemed that the transsexual manifestations were simply part of that illness because they remitted with the treatment of schizophrenia.

Saturday, 28 May 2011

Egyptian Medical Practice, reaching the required standards and maintaining them

First National Conference on Medical Education Development and Improvement in Standard of Living for Doctors
National Training Institute (NTI), Cairo, Egypt

My Lecture:
Egyptian Medical Practice, reaching the required standards and maintaining them, May 2011

Relevant link

Related article, page 8

Thursday, 26 May 2011

Perianal haematoma

This is also called thrombosed external haemorrhoid and it relates anatomically to the veins of the external haemorrhoidal plexus. It is usually consequent upon straining at stool, coughing or lifting a heavy weight (back pressure on an anal venule).

The condition appears suddenly and is very painful. On examination an olive-shaped, blue (resembling a semi-ripe blackcurrant) tense, tender subcutaneous swelling at the anal margin is seen. The haematoma is usually situated in a lateral region of the anal margin. If it is left untreated it may give rise to a skin tag or burst and extrude the clot or bleed. Resolution or fibrosis usually occurs. The condition has been called ‘a 5-day, painful, self-curing lesion’ by Edward Milligan of England.

If the patient presents within the first 48 hours the haematoma may be evacuated under local anaesthesia and the wound is allowed to granulate. If the perianal haematoma is situated anteriorly or posteriorly, it should be treated conservatively because of the liability of the wound in these regions to become an anal fissure.

Tuesday, 3 May 2011


Pachydermoperiostosis (Gk pachys thick) is characterized by hypertrophic changes involving primarily the skin (pachydermia) and bones of the extremities (periostosis). 

Primary pachydermoperiostosis (also called primary hypertrophic osteoarthropathy or Touraine–Solente–Golé syndrome) is a rare inherited disorder and occurs predominantly in males. It is sometimes autosomal dominant (with variable expressivity). At other times, it is autosomal recessive. Primary pachydermoperiostosis usually begins soon after puberty and progresses up to 10 years. Exceptionally, it may continue to progress. The skin of the face, forehead and scalp becomes grossly thickened and thrown into folds (coarse facial features, one of the leonine facies). The folding of the scalp produces one of the forms of cutis verticis gyrata. The skin of the hands and feet is also thickened, but often not folded. Thickening of the phalanges and of the bones of the limbs produces spade-like hands and feet with increased circumference of arms and legs/the fingers and toes are clubbed (related to altered proteoglycan synthesis). Reported associated features include e.g.: acro-osteolysis, sparse facial and pubic hair, gynaecomastia, seborrhoea of the face and scalp, palmoplantar hyperhidrosis, carpal and tarsal tunnel syndrome, and learning difficulties. Arthralgias can be debilitating. There are reports of resolution of the arthralgias when treated with tamoxifen.

Secondary pachydermoperiostosis (also called secondary hypertrophic osteoarthropathy) is usually provoked by serious pulmonary pathology such as bronchial carcinoma and lung abscess. Secondary pachydermoperiostosis occurs predominantly in men aged 30–70 years. The bone changes are the most obvious feature, develop more rapidly, and are usually painful. The skin changes may be absent and are usually relatively mild. When the primary disease is treated effectively, the bone and skin changes will regress. The primary and secondary forms of pachydermoperiostosis must be differentiated by the age of onset, the rate of progression and the presence of underlying pulmonary pathology.

Cranio-osteoarthropathy shares some features with primary pachydermoperiostosis [clubbing and hypertrophic osteoarthropathy], but patients do not have pachydermia. They typically present earlier in childhood and have delayed neurocranial ossification, with delayed closure of the fontanelles, and may also have congenital heart disease. Having said so, the overlap of clinical features suggests that primary pachydermoperiostosis and cranio-osteoarthropathy are allelic in some patients. In acromegaly, the facial skeleton, jaw and skull as a whole are enlarged, and visual defects may be detectable. In thyroid acropachy, enlargement is confined to hands and feet, and exophthalmos and pretibial myxoedema are often present, with other signs of hyperthyroidism.

Friday, 29 April 2011

Primary anetoderma

Discussed online (synchronous) in April 2011.

The term anetoderma (Gk anetos slack) refers to a circumscribed area of macular atrophy of the skin associated with a loss of dermal substance on palpation and a loss of elastic tissue on histopathological examination.

Primary anetoderma implies that there is no associated, localized, underlying cutaneous disease, whereas true secondary anetoderma can be attributed to some associated condition though the atrophic areas do not always develop at the sites of the known inflammatory lesions.

Primary anetoderma has been divided into the Jadassohn–Pellizari type, in which the lesions are preceded by erythema, and the Schweninger–Buzzi type, in which there is no preceding erythema. The two types of primary anetoderma can coexist in the same patient, and the prognosis and histopathology are identical in both. Thus this differentiation is of historical interest only.

Primary anetoderma is strongly associated with antiphospholipid antibodies with or without a prothrombotic state.

A middle-aged woman presented with skin coloured to pink sac-like protrusions 1–2 cm in diameter, mainly on upper arms and back that have developed over many years and remained unchanged. The lesion surface was thinned and on palpation the examining finger sank into a pit (buttonhole sign). The protrusion reappeared as soon as the pressure from the finger was removed. Coalescence of smaller lesions gave rise to larger protrusions. The lesions arose on clinically normal skin. Few lesions were depressed. There was no history of underlying associated skin disease. Histopathology was consistent with anetoderma. Diagnosis of primary anetoderma was made. The key defect in anetoderma is damage to the dermal elastic fibres (focal elastolysis). Antiphospholipid antibodies have not been detected in the patient. No regularly effective treatment has been found.

Thursday, 10 March 2011

British National Formulary (BNF)

Each new edition of the BNF/BNFC is updated with the latest medicines information and guidance on best medical practice.

This page was last updated in April 2012.

Thursday, 13 January 2011

Diagnostic Test Performance

Sensitivity: PIDPositive In Disease” = true positive / all who are really diseased (true positive + false negative by that test)

Specificity:  NIHNegative In Health” = true negative / all who are really disease free (true negative + false positive by that test)

Positive Predictive Value (PPV):  true positive / all +ve results by that test in other words true positive + false positive

Negative Predictive Value (NPV):  true negative / all –ve results by that test in other words true negative + false negative

In simple words:

Sensitivity: probability of a positive TEST result if the patient is diseased.

Specificity: probability of a negative TEST result if the patient is not diseased.

PPV: probability that a PATIENT tested positive is indeed diseased.

NPV: probability that a PATIENT tested negative is indeed not diseased.

The predictive value of a test not only depends on its sensitivity and specificity, but also on the disease prevalence.

The more prevalent the disease, the higher the positive predictive value of the test and the lower its negative predictive value and vice versa.

This may confuse some, as one might say, why on earth would the prevalence be affecting the whole issue in the population tested?

The following example will clarify it:

Using a test with a sensitivity of 100 % and a specificity of 99 % (i.e. 1 false positive in 100), and screening 1,000 patients, one would expect to see the following:

*In a setting with a high disease prevalence of 10 % (i.e. 100 per 1,000)
100 true positives per 1,000
10 false positives per 1,000 (constant)
Positive predictive value: 100 true positives/110 total positives = 91 %
100 (91 %) of the 110 positive test results are true.

*In a setting with a low disease prevalence of 0.1 % (i.e. 1 per 1,000)
1 true positive per 1,000 (this figure is now significantly lower as the disease is less prevalent)
10 false positives per 1,000 (constant)
Positive predictive value: 1 true positive/11 total positives = 9.1 %
Only 1 (9.1 %) out of 11 positive results is true.
In other words, >90 % of patients tested positive in a low-prevalence population will be actually false positives!

Saturday, 8 January 2011

Sexually Transmitted Infections (STI) testing update

Silver Jubilee ESDV Conference 
Marriott Hotel, Zamalek, Cairo, Egypt

Sexually Transmitted Infections (STI) testing update, January 2011.

Note that a test of cure is now recommended for ALL cases of gonorrhoea (culture should be delayed for at least 72 hours and NAAT at least 2 weeks after treatment).

This page was last updated in July 2011.

Management of Erectile Dysfunction in hepatic insufficiency

Egyptian Association for the Study of Gastrointestinal and Liver diseases - Special Interest Group Liver and systemic diseases Conference, Management of Erectile Dysfunction in hepatic insufficiency, October 2009.

HIV Vaccine and Vaccines in HIV infection

World AIDS Day (WAD) Conference, Kasr El Aini School of Medicine, Cairo University, HIV Vaccine and Vaccines in HIV infection, December 2007.

Sexually transmitted diseases pattern among men attending a specialised hospital (El-Haud El-Marsoud), thesis


My thesis dealt with different aspects of sociocultural and socioeconomic factors together with sexual orientation that interacted with sexual attitudes and practices of my patients at the Sexual Health Clinic, El Haud El Marsoud Hospital (
a hospital with walk-in clinics, for skin and venereal diseases in Cairo, established by the UK in 1902). The USA Government provided the hospital with a suitable STD laboratory at the time. 

Gohar A. Sexually transmitted diseases pattern among men attending a specialised hospital (El-Haud El-Marsoud). Cairo University, 1993.

Sexually transmitted urethritis was the commonest STD in my study.

Syphilis ranked the second among the diagnosed STDs in my study.

Anogential warts ranked the fourth among the diagnosted STDs in my study. 

Genital mollusca contagiosa ranked the sixth among the diagnosted STDs in my study.

Other relevant photos:

This page was last updated in February 2016

Main Works of Reference List (The first eight are my top favourites)

  • British National Formulary
  • British National Formulary for Children
  • Guidelines (BAD - BASHH - BHIVA - Uroweb)
  • Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health
  • Oxford Handbook of Medical Dermatology
  • Rook's Textbook of Dermatology
  • Simple Skin Surgery
  • Weedon's Skin Pathology
  • A Concise Atlas of Dermatopathology (P Mckee)
  • Andrews' Diseases of the Skin
  • Andrology (Nieschlag E FRCP, Behre M and Nieschlag S)
  • Bailey and Love's Short Practice of Surgery
  • Davidson's Essentials of Medicine
  • Davidson's Principles and Practice of Medicine
  • Fitzpatrick's Colour Atlas and Synopsis of Clinical Dermatology (Klaus Wolff FRCP and Richard Allen Johnson)
  • Fitzpatrick’s Dermatology in General Medicine
  • Ganong's Review of Medical Physiology
  • Gray's Anatomy
  • Hamilton Bailey's Demonstrations of Physical Signs in Clinical Surgery
  • Hutchison's Clinical Methods
  • Lever's Histopathology of the Skin
  • Lever's Histopathology of the Skin (Atlas and Synopsis)
  • Macleod's Clinical Examination
  • Martindale: The Complete Drug Reference
  • Oxford Handbook of Clinical Examination and Practical Skills
  • Oxford Textbook of Medicine
  • Practical Dermatopathology (R Rapini)
  • Sexually Transmitted Diseases (Holmes K et al)
  • Statistics in Clinical Practice (D Coggon FRCP)
  • Stockley's Drug Interactions
  • Treatment of Skin Disease: Comprehensive Therapeutic Strategies
  • Yen & Jaffe's Reproductive Endocrinology