Monday, 30 June 2014

Thursday, 12 June 2014

Thursday, 5 June 2014

Situations to remember (3)

WhatsApp diagnosis and missed biopsy

The female child has been diagnosed with bacterial skin infection affecting the scalp and the neck that responded well to antibiotics prescribed by another dermatologist. When the problem recurred she came to see me and I have seen the last prescription that was full of medications including steroids. While waiting for the culture and sensitivity result she received a short course (3 days) of broad spectrum antibiotic (amoxicillin with clavulanic acid). I was then on holiday, thus I was sent the result and follow up photos on WhatsApp. The result proved negative and the rash was extending. On WhatsApp my diagnosis has been generalized pustular psoriasis (GPP) or acute generalized exanthematous pustulosis (AGEP) and I have recommended immediate management including skin biopsy and patch testing. When I mentioned so I was told that “they” have made the same diagnosis. It was revealed later that other dermatologists have seen the extending rash while I was on holiday and prescribed methotrexate at the same time when the oral antibiotic course has just finished. The rash quickly disappeared. I saw her earlier today at my clinic and explained this “situation to remember”.  Rook’s states that it is probable that some cases previously reported as drug-induced GPP may in fact have been AGEP. AGEP is an acute, spontaneously healing reaction to drugs, usually antibiotics.  It looks similar to GPP. The presence of eosinophils in the inflammatory infiltrate is a helpful pointer to a drug cause and the spongiform pustulation at the margins is never as prominent as the spongiform pustules seen in pustular psoriasis. Interestingly, AGEP is more common in patients who have a history or family history of psoriasis. GPP itself might be provoked by drugs including withdrawal of systemic steroid therapy. Patients may have phases of ordinary psoriasis before or after the GPP.

This page was last updated in June 2014

Monday, 2 June 2014

Onychomadesis following hand foot and mouth disease

Onychomadesis (Gk madesis, shedding), proximal nail separation extending distally, is a progression of profound Beau’s lines. Onychomadesis may reflect local or systemic upset (including drug induction) and in the latter may result in temporary loss of all nails. Onychomadesis following hand-foot-and-mouth disease (HFMD) was first reported by Clementz et al in 2000*.

This 2-year old male child who recovered from HFMD one month ago presented with onychomadesis affecting the fingernails. No laboratory tests are indicated in the diagnosis of HFMD but if an epidemic is suspected, stool, throat and skin vesicles cultures can be helpful in determining the viral strain and possible complications. No treatment was required.

Onychomadesis in another child with similar history

*Clementz GC, Mancini AJ. Nail matrix arrest following hand-foot-mouth disease: a report of five children. Pediatr Dermatol 2000;17:7–11.

This page was last updated in August 2015

Kaposi sarcoma misdiagnosed as actinic lichen planus‏ in an HIV positive patient

The condition has been misdiagnosed by two dermatologists as actinic lichen planus for 5 months. 

Related article

Kaposi sarcoma (KS) is the commonest tumour in patients infected with HIV. It is an AIDS-defining illness and is caused by a γ herpesvirus, the Kaposi sarcoma herpesvirus (KSHV), also called Human Herpesvirus-8 (HHV-8).

It is recommended that KS should be confirmed histopathologically (healing of the biopsy site). 

Histopathological clues to Kaposi's sarcoma:

• Abnormal tissue spaces in the dermis
Promontory sign (small vessel protruding into an abnormal space)
Haemosiderin and plasma cells
Stuffing of all dilated neoplastic vessels with red blood corpuscles in the absence of plasma
• Established lesions have the usually documented features.
This page was last updated in November 2014

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)
  • Ackerman's Resolving Quandaries in Dermatology, Pathology and Dermatopathology
  • 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